我的妹妹哪有这么可爱。

Older brother Kousaka Kyousuke (17) and younger sister Kousaka Kirino (14) have been in a state of cold war for the past few years. Starting from a certain point, Kirino no longer even greets her brother when she sees him, only glaring at him with a look as if she's seen something filthy. Kyousuke believes this relationship will continue on like this forever. One day, Kyousuke finds a DVD case for a magical girl anime he's never seen before, "*Stardust Witch Meruru*," at the entrance. Inside, however, isn't the anime DVD, but a disc for an adult game "*Love with My Little Sister~*." During dinner, Kyousuke tests the waters by bringing up Meruru to see who the disc belongs to, but only receives prejudiced dismissals from his parents. That very night, the sister who wouldn't even greet him suddenly comes to Kyousuke's room, saying she has something she wants to discuss. It turns out Kirino has become obsessed with moe anime and little sister characters in bishoujo games, but has been too afraid to tell anyone, keeping it all bottled up inside. After her secret is discovered by her brother, she begins her "life counseling" sessions with him.