Summary:

Having defeated the Demon King, the Hero Party sets out on a triumphant journey. Isolde, a magician who is also a princess and has accompanied the Hero Leon on his journey, reads his diary and learns that he loves her and intends to ask her to marry him as a reward for defeating the Demon King. However, Isolde has a secret that she cannot tell anyone. In her previous life, she lived as a man in Japan on Earth. She would never accept marrying a man. With one week left until they arrive at the royal capital, Isolde devises a desperate plan. She will avoid the marriage by pairing Leon with either Thief Nina, Leon's childhood friend who has feelings for him, or the Saint Clarissa! However, the naive Thief misunderstands, and her attempts to persuade the Saint fail. The time limit is fast approaching. Cornered, the TS princess begins her plan to avoid marriage.