A sibling who genuinely hates you suddenly needs your help, and the show builds something real from that friction instead of erasing it. Kirino stays sharp and difficult even as she softens. The romance engine runs on actual character change, not forced reconciliation, which means every conversation carries weight because you're watching two people who spent years ignoring each other learn how to exist in the same room. The ending will destroy half your audience and vindicate the other half. It costs you nothing to find out which side you land on.

Kyousuke Kousaka is an ordinary seventeen-year-old high schooler in Chiba, and for years his fourteen-year-old sister Kirino has ignored him and treated him with scorn. Then he finds a magical girl anime DVD case in the entryway of their home, and inside is an adult game instead of the disc. When he raises the anime at dinner, Kirino abruptly leaves the table, and he concludes the case must be hers. Late that night she drags him into her room and reveals a huge hidden collection of anime, manga and visual novels. To protect her polished reputation as a top student and model, Kirino swears him to silence while pulling him into her otaku hobbies, and through her he meets fellow fans Ruri Gokou and Saori Makishima. The comedy draws on sibling friction and a secret that gets harder to hide the more involved he becomes.