Half-brothers Touma Amazuki and Haruyo Amazuki run a small but hidden popular restaurant called "Solliev0". Apart from the food, the restaurant has a "secret menu" that solves the problems of customers who visit the store, and together with his childhood friend Torataro Kujo and his friend Sora Hojo, he is living a successful life working on hospitality and solving problems. Ta. In fact, Haruyo, who is the heir to the Amatsuki family and the owner of the conglomerate company Amatsuki Holdings, had made a promise with his father, Jira, who is the current company president, that he would inherit the family when he turns 30. As the deadline passes, it becomes clear that Jira has only a short time left to live. As if to coincide with his death, Fuyuma gradually changes from his previous role as his older brother. What is Touma's true purpose?