Noboru went to a local school and continued to live in a dormitory. Three years have passed and the graduation ceremony has finally arrived. On the way home while soaking in memories, it was her mother-in-law, Maki, who came to the graduation ceremony with a surprise and appeared with a smile from behind. She secretly enjoys a celebration alone with her longing mother-in-law ... Maki drinks too much and she is sent to the hotel. Noboru keeps reason not to have an evil feeling for her defenseless girlfriend. However, Maki gently entwined with his body, step by step on the adult stairs ...