My younger sister, Mitsuki, is a junior high school student. Recently, Mitsuki has begun to awaken to sex, and she seduces me day and night. What's more, my parents are going on a two-day hot spring trip starting today, so they'll be away from home. Mitsuki takes this opportunity to start teasing me as soon as she wakes up, so it's just crazy! *There are no performers under the age of 18 in this work.