Kotone's feelings for her younger sister Maria escalate and finally cross the line! The forbidden love begins with the scent of Maria's underwear, and the uncontrollable emotions explode at school, and when they return home, the two of them fall into carnal desire! I want to kiss Maria, I want to see Maria's pleasant face, I want to lick Maria's pussy, I want her to show everything to me... Kotone's obscene thoughts accelerate!