In a world where Western and Chinese cultures blend, the only son of the Kioh Empire's Kikunoi Viscount family, Ageha, found himself at the end of his rope at the age of five. Overweight and friendless, he suddenly learns that his younger brother, Regulus, might one day kill him for the right to inherit the family title. His only weapon is the sudden return of his past life memories as a Japanese person, specifically his skills in cooking and sewing. Despite the odds, Ageha ends up raising his brother, who turns out to be incredibly adorable. He throws himself into his role as an older brother, making educational toys and developing new dishes like chawanmushi. Using his past life's expertise in household management, he gradually improves the troubled estate. This is a heartwarming fantasy about young siblings transforming their land and even the nation, one small step at a time.