Most films about the disabled are worthy - and not necessarily dull - stories about individuals trying to overcome difficulties. Late Bloomer, a new Japanese film directed by 29-year-old Go Shibata, is a little different. It tells the story of a disabled young man who falls in love with his attractive young helper - and murders anyone who becomes romantically attached to her. It's a tense drama, rather than a horror film - and the confused killer is played by wheelchair-bound actor Masakiyo Sumida. Like his character, Sumida suffers from multiple handicaps. He has limited motor functions and can't walk at all. He can't speak, but he can use his fingers to tap out Japanese characters one-by-one on a Namco speech machine, that runs the characters together and generates a full sentence in a synthetic voice. Unlike the fictional killer, who's moody and self-obsessed, Sumida is an extrovert who says he's thrilled to be starring in a film that's showing at international film festivals. He has an infectious charm that seems to impress everybody. He's got such a lust for life, he's not the kind of person to feel sorry for. Sumida, using the speech machine, says that he's not new to acting, although Late Bloomer is his first film. He's a regular at an acting workshop for the physically challenged. His helpers at the hospital thought he had some acting talent, and used to joke to him about making a film. Then one of them contacted Go Shibata- and the joke became a reality. The director asked him to suggest a theme for the film. Sumida and his helpers decided a psycho-killer drama would be more fun than a worthy film about the problems of being handicapped. 'My helpers had the initial idea,' Sumida says. 'They wanted me to think of the thing that would be most impossible for a physically challenged person to do. Then we'd suggest that for the subject of the film. Being violent and killing people is something that's very difficult for a physically challenged person to do. It's difficult to get close to people without them noticing if you're in a wheelchair, and even more difficult to kill them, as you can't move very fast. So we settled on a serial killer as the subject of the film.' The story, adds Shibata, grew as he was working with Sumida on the set. 'It was the first time I had worked with a physically challenged actor,' the director says. 'My main worry was how I was going to direct the acting. That confused me at the beginning - I couldn't just say 'here's your part, act', to him. So I decided to connect his personality to the film. I observed him a lot and I used what I saw in the film.' The more he understood the mind of the actor, the more interesting he was able to make the script, Shibata says. 'I communicated a lot with him while we worked - it was very much a two-way process. I tried to figure out what his biggest frustrations were as a handicapped person, and then put them in the story. I experimented with making him feel frustration and anger on the set, and I wove those real emotions into the narrative.' Sumida is grinning as he listens to Shibata's version of events. He taps more letters into his speech machine in response. 'I didn't ever feel angry or frustrated when we were making the film,' he says. 'I was actually just pretending. I was just giving the director what I thought he wanted.' But Sumida says the problems he encounters in daily life helped him get a grip on the mind of his murderous character. 'I have a natural kind of anger which comes from all the things that have happened to me,' he says. 'I certainly drew on my frustrations when I was planning the character. But when I was actually acting in front of Mr Shibata, my head was completely empty.' The actor and director became good friends while making the film, and have a solid rapport. Shibata seems to have developed an instinctive knowledge of what Sumida is trying to say, and will often step in to clarify and expand on the short sentences that emanate from the speech machine. 'We really got to know each other well while we were shooting,' says Shibata. 'In fact, we got more and more frank with each other as time passed. He would often call me an idiot on set, as he didn't always agree with what I was doing with the story. It was a kind of war: me and my film crew versus him and his helpers.' Sumida agrees. 'We had a lot of fights.' Some critics have interpreted the story as a metaphor for the problems of the physically handicapped. Others feel it's a passionate personal drama. Sumida, who works for a department that tries to help the physically challenged lead independent lives, says that when they were making the film, they didn't really consider what genre it was. 'We didn't deliberately mean to make it either a personal story or a metaphor to show the problems that disabled people have. We just told our story. People who are watching the film can see it either way.' Sumida says if he gets the chance to perform in another movie, he wants to play 'someone who's pulling all the strings - a puppet master'. He admits that he found the murders in Late Bloomer - which include a clever poisoning - stressful, although he enjoyed the experience overall. His physically challenged friends were all impressed with his work. 'Some of them cried at the sad bit - but mainly, they all got very scared.'