友達の妹が俺にだけウザい

Akiteru Oboshi, a high school student, runs the indie game dev circle 5th Floor Alliance. His problem is Iroha Kohinata, the younger sister of his best friend Ozuma, who bullies him at every opportunity, a far cry from the model honor student everyone else sees. Things get more complicated when his uncle offers support for the circle on one condition: Akiteru must pretend to date his cousin Mashiro Tsukinomori, who is transferring to his school to escape her own troubles.