Noboru went to a local preparatory school and continued to live in a dormitory. - Three years have passed, and the graduation ceremony has finally arrived. - On his way home, immersed in memories, his mother-in-law, Maki, who came to the graduation ceremony as a surprise, appeared from behind with a smile on his face. - He enjoys celebrating alone with his mother-in-law, who he secretly admires, but... - Maki drinks too much and is sent to a hotel by him. - Noboru maintains his rationality so as not to harbor any evil feelings toward his defenseless girlfriend. - However, Maki gently wraps around his body and takes him one step at a time on the stairs to adulthood...