The protagonist's long break is over, and a new school term begins. Somehow, Reviola and Miris are there as he goes to school. "Because we're worried about Yū-chan, we older sisters will go with you♪" The two have actually decided to attend the protagonist's school, as a student and school doctor, respectively. Naturally, this leads to— "You made it to school! That's amazing! You made it through the first period! That's amazing! You made it to lunch break! That's amazing!" and so on... they repeatedly give the protagonist lewd rewards as excuses. The protagonist's excessively lewd school life with his devilish older sisters begins.