Kyousuke Kousaka, a regular high school student, has a distant relationship with his younger sister, Kirino. Their dynamic is strained until Kyousuke stumbles upon a DVD case of a magical girl anime that unveils a surprising secret. As he delves into this discovery, their worlds collide over a shared interest in anime and games, sparking a conversation that leads to a hidden trove of Kirino's moe anime and bishoujo games.