0.5 Man.

Masaharu "Masaji" Tachibana was a brilliant programmer who got burnt out and suddenly stopped showing up to work. He now lives at home with his parents and spends his time sleeping and playing video games. He only ventures out of his room to visit the local convenience store for more energy drinks and snacks, until one day he learns that his parents have decided to build a "2.5 family" house with his sister and her family joining them. Masaji is forced to acclimate and with the change of environment begins to venture out of his room and his own head.