Based on

Movies like Cain's Descendant (2007)

Munakata has an unrelenting guilt from killing his mother when he was 15 years old. After being imprisoned for 10 years, he is released and heads to Yako, a small industrial town, to work as a machinist. Living in a tiny apartment, he is tasked with secretly creating a gun out of an old TV remote control and unknowingly destroys the fragile balance of the town.