For the past 12 years, Mr Kenny Lim has slept only three to four hours a night. Every day, from 9pm to 3am, he plans, assembles and paints his Gundam robot model kits.
"Sometimes, I run on coffee and Red Bull. But I'm happy to forgo sleep for my passion," says the 37-year-old claims executive in an insurance company, who is married with two young children.
Later this week, he will make a pilgrimage to Takashimaya Square, where more than 200 models of the Japanese popular robot franchise will be shown at what is Singapore's biggest Gundam event to date.
Two 6m-tall robots, each weighing 2 tonnes, will be placed at Ngee Ann City Civic Plaza. Gundam mechanic designer Kunio Okawara, who created the first Gundam design, is coming here to meet fans on Saturday.
The event, which runs for almost a month starting from Thursday, is to celebrate the 35th anniversary of Gundam model kits.
The model kits have a passionate otaku following - mostly men under 40 - including here, where some fans have amassed more than 500 model kits, filling their bedrooms and homes with the boxes.
Some of them have each spent more than $50,000 on Gundam, not to mention countless hours assembling the models. And they have no regrets, they say, because they are huge fans of the franchise, which also comprises anime, manga and video games.
Mr Lim and Mr Leon Ku, 39, are believed to have among the largest collections of Gundam model kits here. They each own more than 500 kits, which cost from $20 to more than $600 each.
Mr Lim first watched the anime series on TV when he was 16 and bought his first model kit - a $30 Wing Gundam - a year later with his pocket money.
He says: "It's great imagining myself as a pilot controlling a massive robot and taking down foes. Creating the models somehow lets me indulge in the fantasy.
"The hobby lets me express myself creatively. I can pose the figures any way I want and modify them to make them look more impressive."
In 2004, he started a Facebook page devoted to his hobby, which now has more than 6,000 "likes".
Says his wife, recruitment manager Elaine Lim: "I think his hobby is fine because it is creative and keeps him at home. At least I know he is not out drinking or partying."
The model kits also inspire creativity in Mr Ku, who is drawn to the challenge of making realistic Gundam models through detailed painting and weathering effects.
The building manager, who is married with a son, 10, and a daughter, 13, started assembling Gundam models in 1998. By 2004, he had completed 1,000 models and has since lost count.
He says: "At my fastest, I made four models a week. Some people think I'm just playing with plastic. But I want to show them that making Gundams can be a form of art."
Another collector, food and beverage manager Lin Zhisheng, owns more than 250 kits, mostly kept in his bedroom.
Says the bachelor, 27, who lives in a four-room flat in Serangoon with his mother and sister: "I'm drawn to what Gundam models represent - freedom, courage and willpower."
His favourite - and most expensive - model is an 80cm-tall Neo Zeong, which he bought for $300 last year at a hobby shop here.
Says his sister Zhili, 26, a graphic designer: "When I visited Hong Kong last year, I had to bring back a few Gundam model kits for him.
"He's quite obsessed. But I can understand because I myself collect sneakers. I guess we all have our own weird obsessions."
Mr Bernard Cher, 39, who owns M Workshop, a model kit store at Sunshine Plaza, says that Gundam models must be assembled and painted before they can be displayed.
He adds: "It's not like Transformers or Sailor Moon where you can just buy the figurines and display them immediately. To get a finished Gundam robot, you need patience and skill to put it together."
Limited-edition merchandise will also be sold at the upcoming exhibition and Mr Lin plans to queue overnight to get his hands on them.
He says: "They won't be available anywhere else, so I don't mind queuing overnight to get them."