The fantasy world of a comic boy

The boy who was born with lower limb paralysis is a cartoonist. He drew a cartoon using himself and his disabled friend as characters. The story is mostly straight out of his comics: two disabled teenagers looking for a reason to live get involved with a tough, macho wheelchair killer who is a former firefighter. The two teenagers assisted the killer in completing the mission, but they were a bit in the way. The boss of the hired killer decided to kill these three people, but failed. The boy and the killer went to ask the boss for money. In the fight with the boss, both the killer and the boss died. But the reality outside the comics is...