My Brother is a Pervert Who Becomes More Open in Summer

Ane Log: Big Sister Moyako's Never-ending Monologue · Episode 3 · “My Brother is a Pervert Who Becomes More Open in Summer”

When Konoe Moyako and her little brother, Akira, were young, he said he wanted to marry her. Naturally, Moyako decided that her little brother was a complete pervert who was obsessed with her. Now that they're both teenagers, Moyako is convinced she needs to "rehabilitate" him. However, it seems...