Asian movie about a boy genius


I need help that I canít remember this movie. Itís probably Korean/Japan/China/Taiwan (Asian)) movie about a boys/teenager (probably 4 boys) who worked at a junk shelter. The main character is a genius boy who really good at mechanic/computer thing. The other boy (second) character in the end is passed away because of his illness from a wound. Itís a great movie and I want to rewatch. Please Help. Thanks