After divorcing her husband 10 years ago, Lina raised Taichi by herself, and Taichi, who grew up, was able to get a job at a real estate company. However, Taichi refused to move from his home, which takes more than an hour to get to the office one way. Lina was worried about Taichi, who never took a day off, went out to play, and never brought her friends or girlfriend. Sometimes Lina invites Taichi to a hot spring trip to take her out.