'Where's the Hello Kitty shop?' demands Bernard Sumner of the nearest taxi driver. 'Take me there. To Kitty World!' he bellows, leaping in. Then, seeing me, insists: 'It's a lap-dancing club, right?'

Right! Not so long ago, New Order's baby-faced singer and guitarist would have gone lap-dancing all night and sworn blind to journalists that he was at a toy shop. But this is New Order Part Two. New Order, The Grown-Up Years. You might have thought that adulthood would hit earlier - after all, every band member is a forty something - but up until 1993, when they were last in the spotlight, 'The most culturally significant British band of the last 20 years' ( Uncut ) lived a defiantly teenage life. 'Everyone up for a party all the time,' recalls Sumner. 'We enjoyed that.'

The music business is designed for just such behavior, but still. At 25 years old, this band is longer in the tooth than any member of Coldplay. New Order put in 17 years at the coalface of hedonism before calling a hiatus eight years ago. Now, they're back. 'What's different?' says Stephen Morris, the drummer. 'Everything. Nothing. We're professionals now.' By 'professionals', he means New Order are less bolshie and more clean-living than they once were. Less likely to walk out on interviews, more likely to get to bed before 8am. But he also means that, for all four of New Order - Sumner, Morris, bassist Peter 'Hooky' Hook and keyboardist Gillian Gilbert - music is now a job, as opposed to a life. These days, there's family to consider. New Order have eight kids between them. Hence, Hello Kitty.

'We say Hello to Kitty in a shop called Kiddy Land, a multi-floored emporium filled with spooky-cute cartoon characters, including the endearing Afro Ken, a small dog with huge hair. New Order load up. Hooky finds a portable karaoke, which he tests boomily in the shop - 'One two one two' - rattling the Gameboys and scaring nearby children. Then, it's off to Shibuya, a neon-strafed shopping area that sells everything a junk-bunny ever desired. Sumner dithers between two identical watches: 'What do you think? Dark face or white face? This one's got a back light...' Everyone else waits for him outside the shop. For an hour.

Soon after, the evening accelerates. There's a meal with the New Order entourage, which includes Arthur Baker, producer and long-standing friend of the band, Phil Cunningham who's been recruited to take Gilbert's place for live work (Gilbert is back home in England), and Billy Corgan of the now defunct US goth-rock group Smashing Pumpkins. Corgan, oddly, appears on New Order's new LP, Get Ready , and will be playing guitar when they perform tomorrow at the Fujiyama festival. Oddly, because New Order are about as Mancunian as you get, and Corgan is very, very American. He calls McDonald's 'the Golden Arches'.

Anyhow, at Corgan's behest, some of us repair to Lexington Queens, a truly rubbish nightclub filled with dippy models. 'He said it was where rock stars hang out,' says Sumner. 'But I think it's the equivalent of the Hard Rock Café.' I go to the toilet and overhear two hysterical girls. 'I told you this was the place to go!' one breathes. 'Billy Corgan's here!'

Hooky soon leaves. Morris never came in the first place. Sumner and Corgan stay on. Corgan drinks water and fends off women. Sumner drinks Pernod and dances to Ricky Martin. Eventually, after a visit to another bar and a jig around the hotel's revolving door, he goes to bed. At 4am. Not bad for a 45-year-old. Old habits die hard. New Order haven't changed quite as much as all that.

The next day, though, we see the difference. Sumner is up and ready at 10 for a charm offensive: seven and a half hours of promotional interviews. In the old days, he wouldn't have bothered. Either that, or he wouldn't have been able to. Sumner has an immense capacity for alcohol but an extreme allergic reaction to it. In the past, he's managed to throw up for 13 hours non-stop. Still, at least he sees the funny side. He relishes his many hangover anecdotes and tells me three in quick succession. The first has him chucking up between his knees in his BMW Z1 ('I couldn't open the doors because everybody would have looked at me'). In the second, he wakes up with his head in a bucket: he'd put it by his bed, leant over in the night to be sick, got his head wedged and gone back to sleep. And in the third, he puts an entire shopping bag filled with puke through the scanning machine at JFK airport ('I didn't know what else to do with it'). You'd never think it - he still looks as innocent as a choirboy - but Sumner is as rock'n'roll as Lemmy.

And, like all of New Order, he is hilarious. Between interviews, he and Hooky keep us entertained with their nonsense and mickey-take. Their main target today is Jayne, their press officer, who got very drunk last night. Hooky, dressed in the twisted Levi's of a man half his age, throws himself round the room, grabs a guitar and makes up a song about Jayne on the spot. Sumner's clothes and body language are calmer, his manner far less confrontational, but his wit is as vicious. He decides that there should be a Fool's Corner, where Jayne can join Cunningham, who Hooky got so smashed at Heathrow that he was sick all over the plane's toilet - before they even took off. Jayne reminds Sumner that he has to get back to the interviews.

'Oh, the interpreter knows all the answers now,' says Sumner. 'We just go, "Give answer Number 4."'

New Order's humour belies their music, which is emotional but cool, machine-driven, man-made; and their image, rooted as it is in the Southerner's cliché of dour Mancunians. Their humour also belies their history, which doesn't read like a giggle. The band's first incarnation was the doomy, dark-hearted Joy Division, formed by Salford schoolmates Sumner and Hooky in 1976, after they saw the Sex Pistols play Manchester's Free Trade Hall. They pulled in Ian Curtis as vocalist on the basis of his jacket (it had 'HATE' written on the back), and recruited Morris from an advert. Joy Division made one LP, Unknown Pleasures . The band were poised to tour America when Ian, an epileptic, committed suicide, in May 1980. He was just 23.

Joy Division split, then reformed a few months later as New Order, with Sumner on vocals and Gilbert, Morris's girlfriend, joining on keyboards. Soon, the new band found a new sound, based in part on the US electro scene which they'd enjoyed at New York nightclubs. In fact, they were so inspired by those clubs that in 1982, they opened their own version - the Hacienda on Manchester's Whitworth Street. 'So our manager would have somewhere to go and lech at women.' They opened it every single night. No one came. The Hacienda haemorrhaged money. Then, in 1983, New Order released 'Blue Monday', which became the best-selling 12-inch record of all time. Unfortunately, due to the expensiveness of the sleeve, every time a copy was sold, the band lost money. Hooky says it was 50p a copy; Factory record boss Tony Wilson has it at £1. It's more likely to have been around 2p, but even then, that's more than £250,000.

During the 80s and early 90s, New Order released some wonderful, huge-selling records and lost even more money: they opened a bar, Dry 201, that filled at weekends but tumble-weeded during the week. The Hacienda became enormously popular during the acid house years, then crashed due to gangster trouble. Still, though their bank balances were aching, New Order's cool never suffered. They garnered an impeccable reputation for being simultaneously arty and of the people, appealing across dance and rock fans to both 'football hooligans and spotty students', as Sumner puts it.

But they inspired more than just fandom: they affected the future. The Happy Mondays were regulars at the Hacienda, which also launched the careers of M-People's Mike Pickering and DJ-come-writer Dave Haslam. Bands as diverse as Primal Scream and Corgan's Smashing Pumpkins acknowledge their debt to New Order. I remember watching the last ever gig of New Order Part One, at Reading festival in 1993, with James Brown, who was about to launch Loaded . He looked at the crowd and said: 'This audience is who I want to read my magazine.' Hooligans and students. Lads and clever-clogs.

Despite their shared success-genius-history, when New Order finished that Reading gig, they walked off stage and didn't see or speak to each other for five whole years. None of the three factions - Morris and Gilbert are nearly always regarded as one entity - knew whether New Order would get back together. Today, they still seem surprised they did.

What happened, then?

Morris: 'I dunno. Typically, no one said anything. If we were Americans or Europeans we'd have been crying, slapping each other or hugging each other, but we're Northern men. You know: don't say owt, suffer in silence. Leave the room, that'll teach 'em.'

New Order left the room for a long, long time. Since they've been gone, we've had Britpop, Britney, Big Brother. Boy and girl bands are two a penny. Dance music has become pop; indy music has retreated. Is there still room for New Order?

Before they came to Japan, the band played a warm-up gig in Liverpool, with Cunningham and Corgan on guitar. The venue was packed with old faces: Happy Monday's Bez and Rowetta, Primal Scream's Mani and Bobby, Jah Wobble, Dave Haslam. And Gilbert, who watched the gig from the lighting desk until the bloke behind her said: 'Would you mind not moving about so much, my mother can't see.'

'My mother !' laughs Gilbert, when I see her later. She was laughing, but she was upset: clearly, the complainer had no idea that Gilbert was actually in New Order. Gilbert can't come on tour because Grace, her youngest daughter, is ill. She feels left out. 'Like the ghost in Randall & Hopkirk . I should turn up in a white suit, going, I'm not dead!'

The question is, though, are New Order dead? Judging by Get Ready , clearly not: it takes a couple of listens but is as catchy as ever, with a harder, more guitar-layered sound, and Sumner's usual funny (in both senses) lyrics. But eight years is a long time in pop. At Liverpool, the over-30s in the audience were ecstatic to see New Order play. But the under-30s were vague as to who the band actually were: they'd turned up to see Billy Corgan. Outside the band's radar, there was a mild panic as to whether Radio One would play-list 'Crystal', Get Ready 's first single. In fact, it made the C-list, and was promoted to B-list status after a couple of weeks.

Of course, the band don't consider whether they're 'relevant' or not: no band ever really does. And to them, no doubt, the break doesn't seem so long. After all, during their eight years away, none of them actually stopped working: Hooky created two bands, Revenge and then Monaco, which released three LPs between them; Sumner made two albums as Electronic, with Johnny Marr; Morris and Gilbert clocked up their own two CDs as The Other Two. Plus, aside from all that music, there was life, generally, to be lived. Hooky divorced Caroline Aherne and married Becky Jones, an interior designer. They have a child, Jessica. Morris and Gilbert married, after 20 years of dating, and had two daughters. Sumner hung out with his long-term girlfriend Sarah and 'got shit-faced at acid-house parties. And then tried staying in.'

We've decamped from Tokyo to a ski-resort in the mountains where the Fujiyama festival is held. In another restaurant in another hotel, Sumner explains New Order's lost years.

'It was just silly little petty animosities that split us up,' he says, in his Mancunian whisper. 'Thousands of stupid daft things. Like when you see a stone staircase and it's all worn away where everyone's trodden. You can't see it happening, but you can see the results. The results are real.'

Pressed further, Sumner will admit that, by the end, he couldn't stand the way Hooky ate apples ('horrible crunching noise'), or the way he'd suck every one of his fingers when he'd finished a packet of crisps, 'or someone would play a record on the tour bus that I didn't like'. But the real explanation was that, by the end of the 80s, New Order were strung out, Sumner in particular. Never one to enjoy gigging (he prefers recording to playing live), New Order's roistering tours almost finished him off. To enliven the US habit of meet-n-greets after gigs, the band used to turn their dressing rooms into mini-nightclubs. Then they'd skip off to a real club, before continuing the party back at the hotel. 'It'd get to seven in the morning,' remembers Sumner, 'and you'd think right, well, we've got a flight at 8.30, so let's just go straight to the plane.'

Sumner tried retiring early, but he has little will-power, and when he did manage it, would find himself 'sat by myself in a hotel in Kansas City with 56 channels of crap on the television'. All of which would have been bearable, if the business side of New Order hadn't foundered. He remembers coming back home from their last American tour. Hooky and Rob Gretton, New Order's manager, told him that all the money they'd made on the gigs had to be given to the Hacienda, to stop it from going under. All that agony for nothing. 'It just flipped me out.'

In 1992, when New Order were making Republic , there were crisis meetings every week. The Hacienda was bringing in cash, but its debts were so large that the money could only pay off the interest. No chance of converting what was owed into a mortgage because Factory Records was in too much trouble to provide the surety.

Of course, everything collapsed. New Order came out owing £600,000. Then, in the midst of the carnage, someone found a piece of paper signed by the Factory directors that read: 'The musicians own the music and we own nothing.' Which meant that the bands could sign huge publishing deals for all the tunes they'd already written, as well as recording contracts for future music. London records stepped in to claim New Order, 'like the cavalry', says Sumner. Chaos all round. The piece of paper effectively whisked Fac tory's only assets away from the hands of the debtees. Sumner remembers going up in front of the liquidators. 'They just couldn't believe this piece of paper existed. But it did. No contract, just this bit of paper. They tried to make out that we'd written it a couple of days earlier, but honest to God we didn't. But,' he grins, 'if it hadn't existed, we would have written it...'

After all that pain, no wonder New Order scarpered. I was with them for a couple of their last dates, at the Montreux and Roskilde festivals, in summer 1993. I remember Sumner kept the others waiting at sound check for an hour and a half; then turned up, played a couple of chords and left. It makes me think about how he managed to string out choosing between two watches for an hour. 'I'm terrible with decisions,' he agrees. 'And I can't make myself do something I don't like. I can't knuckle under.' Plus, Sumner is used to people waiting for him: when you ask him a question, he takes his time answering it and simply ignores inconvenient distractions, like follow-up queries. He does what he wants, when he wants, for as long as he wants. Nothing happens, really, with New Order, until he arrives. All this means that, when it comes down to it, it was he who broke the band up. Hooky loves to tour, and Morris says that, after two years' break, 'I thought, it's over, the longer it goes on, the less likely we are to get back together.'

Sumner was pretty happy without the others. He took up sailing. He travelled around England with Sarah. He spent time with his kids. Occasionally, there would be phone-calls from Gretton, saying things like: there's a bloke in Dallas who'll pay £1.4m to have New Order play at his daughter's birthday party. But the band wouldn't do it. 'That's how much we hated each other.'

After five years, Gretton got through: he sent faxes to each band member, saying, You've been offered festivals, do you want to do them? They decided to meet. Morris and Sumner turned up wearing the same top. They were all extremely nervous.

'I said: "Has anyone got any problems?"' remembers Sumner. 'And they said: "Have you got any?" And I said: "None at all."'

Hooky insisted Sumner owed him a tenner. And that was it. Within three minutes everything was fine again. 'It was like: what the fuck actually happened?' says Sumner. 'And I'm still not 100 per cent sure what did.'

That was 1998. New Order took things slowly from then on: a couple of festival gigs here, a track for a film there. They decided to make an LP. Recording was at the studio at Morris and Gilbert's farm, in Derbyshire.

I ask Morris what it was like. 'They came in and tore my studio to bits. Going, ooh, I don't like that kind of milk, and I don't like these sandwiches, they're a bit runny.'

During recording, Morris had a routine: he'd get in at 11, fiddle about with music or clean up until someone else turned up, about 1 or 2. When everyone was there, around 2.30, they'd try and work, but then they'd knock off about 5, because of their kids. A slow process. 'Civilised, though. But as time goes on, you lose all that. Sumner's got to write his lyrics at night, you know...'

In the middle of making the LP, Gretton, the band's 'fifth member', their manager since Joy Division days, had a heart attack and died. He was 46. New Order were devastated. And, for Morris, it was the beginning of what he calls 'grief', a series of events that changed him from an eccentric drunk to the more sombre man he is today. His dad became ill and died, then he and Gilbert discovered that Grace, only 18 months old, had a rare virus that affected her spine and meant she could no longer move - though there's hope that she should recover. Soon after, Morris got food poisoning, then chicken pox, then put his back out. He gave up drinking, though he allows himself a glass of wine before he goes to bed. 'I don't see the point any more to getting off your head,' he says, not disapprovingly. 'I'm just... full.'

Morris is the most changed since New Order Part One, especially because Gilbert isn't here. The pair have hardly spent a day apart since they met. 'The Paul and Linda McCartney of New Order,' I say thoughtlessly. Morris cringes. The band used to split nicely into two: Sumner and Hooky, friends since they were 11, noisy, look-at-me rabble-rousers; Morris and Gilbert, quiet, inseparable, though no less anarchic. Morris is a bit swamped without her.

'This (the band) isn't my life any more,' he says. 'It's a small part of my life. It's not like in the past, when, even when we weren't getting on, we were a tribe.'

Do you think: oh, the good old days? 'No, there's films now that do that, aren't there?'

He means Michael Winterbottom's 24 Hour Party People, due out next year, which is due to take a twisted look at Factory Records, from 1979 to 1993. Did you go to the set, the recreation of the Hacienda?

'No. Gillian went, I couldn't face it. I never enjoyed going to the place anyway, and they always made me pay in, even though I owned it. They never recognised me. A trend that continues to this day, actually. People cross the road to give me their autographs.'

It must be strange having films made about your life, when you're not dead yet. 24 Hour Party People isn't the only one. In America, there's a movie proposal about the story of Joy Division, taken from the book written by Ian Curtis's widow, Debbie. You can't imagine anyone fighting for the rights to the story of Travis. But New Order inspire such myth-making. They survived it all: death, drugs, drink, bankruptcy, resentment, crunching apples, terminal lateness. Somehow New Order have come through 25 years with dignity and credibility intact.

The secret, of course, is in the songs. Before the gig, Corgan says to me: 'They're up there with the Beatles. Their catalogue is devastating.' For Fujiyama, New Order showcase some of this devastation for a full 90 minutes. Sumner introduces 'Touched By The Hand Of God' by saying: 'This one's about Hooky's bass.' Hooky is so surprised he nearly falls over: Sumner never once paid him a compliment in New Order Part One. I push through the crowd to the front, to hear 'True Faith', 'Temptation' and 'Love Will Tear Us Apart'. The last two bring tears to my eyes.

And as for Hooky, the most emotional man in pop, he can barely contain himself, such is his joy to be back playing with this band, playing these songs. He says he understands now, having fronted two other bands himself, why Sumner found things so hard. 'Lyrics are a bastard,' he says, succinctly. 'And singing and playing is murder.' So now, he appreciates Sumner's efforts, and Sumner appreciates his. 'I've had two compliments off him,' Hooky says. 'Two, in 25 years. I said that to him and he said: don't get used to it. The little shit. That's why I love him so.'

He wanders off, for another drink. New Order's dressing room is full, as usual: though Morris, and, amazingly, Sumner, have gone to bed. Hooky comes back.

'You know, this is like being reborn,' he cries. 'I feel fantastic. I'm happier than I've ever been in my life. I thank the Lord for Rob Gretton and Ian Curtis. They must be up there rooting for me...'

Life, death, love, hate. Not the glassy emotions of pop, but the blood and joy and terror and tenderness of family. Hooky thinks that, now that New Order's parents have died, the band are tied together for life. And Sumner?

'If you have a bereavement in your family,' says Sumner, 'it's a terrible, terrible thing. But, you know, time passes. It's part of the cycle. It doesn't hurt so much. And for me, the past seems like a dream. Whereas now, I know it's real. Now, is more exciting.'