Mako-San Wa Shindemo Jiritsu Shinai. It has been a year since Rin transferred to secondary school in Tokyo. He was told by his flat's landlord that if he takes care of the landlord's wife, which he instantly agreed, he would not have to pay rent. The granddaughter, Mako, ended up becoming a 20-year-old college student who's utterly unable to take care of herself. Even so, it was Rin's love at first sight, and he has ever since taken care of her.