Mika Yamada is a single never married office worker who lives in a small rental studio. Most of her classmates are married and have children. She often wonders what her life would have been if she had behaved differently 'then.' On her 40th birthday, she received a time machine from her "future relative." She went back to the last date with her college classmate and gave him another chance for his proposal. Then she found herself living as a suburban a housewife. But her husband got killed by a loan shark for her vast shopping debt. So she changed the past back to the original state. It wasn't long before she tried again. She returned to a match-date with a rich man. She found herself in a gorgeous villa as his wife in 2018. However, his head strong live-in mother-in-law controls all household affairs.