It has been three years since my father remarried and I entered a boarding school. Her fruitful student life has come to an end, and Yuu's graduation ceremony has arrived. On her way home with her friend, it was her mother-in-law, Yuna, who ran up to her from across the street with a smile on her face. The two are happy to be reunited after such a long time and celebrate their graduation, but... Yuu takes care of Yuna, who drinks too much due to her happiness. Even though he left her house to shake off his feelings for her, who was the woman of her dreams, she couldn't hold back the feelings that were rising again. And he was once again climbing the stairs to adulthood.