Yu lives alone at a boarding school. The fulfilling student life has finally come to an end, and the graduation ceremony is finally here. On my way home, feeling a little lonely, it was my mother-in-law, Wasaki, who came running up to me with a smile on her face. Delighted to be reunited with the woman of his dreams, the two of them celebrate their graduation together at night... The two of them talk to each other to make up for the time they were apart. Then, ``My gift to you, Yuu-kun, who has grown up...'' Wasaki's slightly wet lips quietly covered his lips... On this day, I was climbing the stairs of adulthood yet again.