His only son, Takane, gifts his mother, Chisato, a 1-night, 2-day trip with his first paycheck. The inn they choose only has mixed baths, so to protect Chisato from other guests, they decide to bathe together. However, this choice becomes a turning point in their relationship. The mother, seeing her late husband in her son, and the son, secretly admiring his mother as a woman. But is that really a bad thing? Isn't it okay to have a lifelong partner within the family? Isn't it okay for a mother and son? After all, it's happiness, happiness... .