After being dumped by her fiancé, the prince, in front of the public, Yuria is offered as a bride to the Demon King of the Demon King's territory. Shocked, she recalls her previous life as a 29-year-old overworked Tachibana Chika. However, upon entering the Demon King's territory, she is told that the marriage is not forced and is given a palace to live in freely. Yuria, thinking positively, starts her slow life. With her past life's knowledge, she improves the Demon King's internal affairs, changes the diet of the demon territory, and even upgrades a fluffy Ketsi to a holy beast level. She is loved by the demon maids and the Demon King's Four Heavenly Kings, and eventually, she and the Demon King fall in love, leading to a happy engagement. However, the human king and cardinal demand her return, summoning a hero who is cynical and suspicious. The hero, who had a fulfilling life in Japan, is eager to return. The story unfolds with the Demon King, the holy maidens, the prince, and the hero, leading to an unpredictable outcome. ❇︎ There is no schadenfreude or cruel treatment for the prince and the new holy maiden. ❇︎