Takeuchi Hitomi, a serious and sincere woman working at a major bank. For over 13 years, she has abstained from any relationship outside her marriage. However, her marital life has been reduced to pregnancy-focused sex solely for conceiving a child. Dissatisfied with this situation and driven by the desire to experience life as a woman before becoming a mother, she makes the decision to embark on her first affair. Surrounded by temptation and guilt, she reveals a completely different side of herself during daytime hours, captivating viewers with her irresistible charm.