Ore no Imouto ga Konnani Kawaii Wake ga Nai

Synopsis

Kirino hangs out with Saori and Kuroneko again and is surprised to find that they do not have to worry about hiding their hobbies. Later that day, Kirino's father learns of her hobby and becomes angry at her. Kirino becomes upset that her hobby has been called "worthless" and runs off, prompting Kyosuke to catch up with her. After seeing Kirino show no desire to give up a part of her life, Kyosuke stands up to his father for her. Though he allows Kirino to keep her hobby, he still shows concern for the eroge Kirino had been seen with, so Kyosuke claims they are his, earning him a punch in the face. Kirino later gives her thanks to Kyosuke, who is taken aback by her unexpected cuteness.

(Source: Wikipedia)