The Boxer, Vol. 11 (Manga) 拳擊手

The dark basement room was all Yu knew growing up. His days were spent eating the same meal, sleeping on the hard floor and comforting him and his mother's wounds after Yu's father would visit them. However, one day something from the outside wanders into Yu's world, and as he learns about the world outside the basement, something new is allowed to trickle into his life--hope. But hope is a fickle thing and as it's stripped away, Yu stares down his final opponent in a boxing ring, with nothing to live for except to knock down anything that stands in his way.