SDMF-044 — At Home, I Make My Sister Wear A School Swimsuit So I Can Slide It Aside And Insert It Whenever I Want. ~ Her Underdeveloped Body, Which Has Never Known A Man, Is Overcome By Her Brother's Twisted Love ~ Kaede Kirari

That was in our second year. I don't know what happened at school, but my brother stopped going out of his house... "Big brother... I know. You have my school swimsuit..." Anyway, I wanted to cheer up my brother, and with that single-minded desire, something happened that we kept secret from Mom and Dad... Maybe it wasn't my brother who changed, but me.