Synopsis: Tenjou no Shita ni Koi

Due to his parents' occupation, Yuito Kanzaki had mainly resided in New York, but now he was preparing to return to Japan alone. Unfortunately, his parents were deeply involved in his life and had a close relationship with their boss, and thus had arranged for him to stay with the Ooji brothers, their boss' offspring. However, Yuito discovered that the household was disorganized and less than ideal for him. Upon enrollment in a new school, Yuito was greeted by the eldest Ooji brother, Ousuke, who was his natural science instructor. Ousuke acted as an elder sibling and was very reliable. The second-oldest brother, Kaisei, was reckless and had a terrible disposition; he had a notorious reputation for being a ladies' man. The third brother, Hotaka, was pleasant and always willing to offer a helping hand. The four siblings, along with Yuito's assistance, worked arduously to look after their youngest brother, Seishirou. As Yuito became accustomed to his new family, he discovered that there was more than met the eye. He was thrust into a world of sibling competition, jealousy, and romance. He had to make tough decisions and be cautious in how he handled these situations to prevent tearing the Ooji family apart.