Mako-san wa Shindemo Jiritsu Shinai

Rin Touno moved to a Tokyo boarding house a year ago to attend high school. The landlord offered him free rent in exchange for looking after his granddaughter, Mako Kurihashi. Mako is a 20-year-old college student who is unable to take care of herself and often mocks Rin for being younger. Despite this, Rin became instantly infatuated with her and has been caring for her ever since. Unbeknownst to him, Mako shares the same feelings.