My Little Sister Can't Be This Cute.

On the day of Kyousuke's high school graduation, he has a final reunion with the gaming club. After the graduation ceremony, Kirino arrives to pick Kyousuke up following the end of her middle school graduation, and both head out to meet Manami. As the group sit in the park, Manami becomes visibly angered upon learning of the Kosaka siblings' relationship and following Kirino's provocation, they start physically fighting. After Kyosuke realizes that the person that has told Kirino that she could never be with her loved one was actually Manami, breaks them up, and cites that she was too harsh to actually force such a truth to a little girl.