Ep 10. My Little Sister Can't Be Cosplaying Like This

It's time for the school cultural festival, and Kirino wants to participate in a cosplay event. She just needs to convince her friend Ayase to dress up as well. However, Ayase is strongly against cosplay, as she believes it goes against her conservative values. Kirino is determined to change her friend's mind, and enlists the help of her brother Kyosuke to convince Ayase that cosplay can be fun and harmless.

Meanwhile, Kyosuke is struggling with his own feelings towards Kirino. He's always been there to support his sister's hobbies, but he's starting to realize that his feelings may run deeper than brotherly love. He tries to distance himself from Kirino, but is unable to resist her charms. As they work together to convince Ayase to join their cosplay group, Kyosuke finds himself falling deeper into Kirino's web.

The cosplay event becomes a huge success, and Kirino is overjoyed that she was able to share her hobby with her friends. However, as the night wears on, tensions rise between Kyosuke and Ayase. Ayase accuses Kyosuke of leading Kirino down a dangerous path, and Kyosuke realizes that he can no longer hide his true feelings. He confesses to Kirino, and is shocked when she admits that she has feelings for him as well.

In the end, Kirino and Kyosuke's relationship reaches a new level of intimacy. They decide to keep their feelings a secret, knowing that their family and friends would never understand. As the cultural festival comes to a close, Kirino can't help but feel grateful for her brother's unwavering support, and can't wait to see what other adventures they will have together in the future.