Yuki and his girlfriend planned to go to a concert together tonight. He intended to leave early but ran into Minami, who asked for his help to complete a document for tomorrow as her boss was going on a business trip, and she wouldn't be able to finish it alone. With only 30 minutes until the next train arrived, Yuki agreed to help. However, it took much longer than expected, causing them to miss the beginning of the concert. As a thank you, Minami invited Yuki to grab something to eat. Due to being engrossed in drinking, Yuki lost track of time, only to realize that the last train had already departed. Minami then invited him to stay overnight at her place. Upon arriving at her home, Minami seemed much more relaxed, wearing loose clothing and no underwear! Yuki could clearly see the most intimate parts of her body! It seemed like Minami did it intentionally, as she made intimate moves towards him that Yuki couldn't resist. They engaged in passionate lovemaking throughout the night until the next morning. For the first time in his life, Yuki experienced new sexual positions and intense kissing sessions that he had never done with his girlfriend...