Minai is Wataru and Akio's friend in Tokyo that was ranked second in grades to Wataru. It's obvious that he's more concerned about being the number one student in their class, and when he sees Wataru again later in the series, he considers him a rival more than a friend. Initially, he was part of their plan to become the elite men in society until Wataru's failing the exam changed everything.

Wataru Minakami is a top student who failed his high school entrance exam because of a computer glitch. He later discovered that he was accepted to Stargazer Hill Academy, which is located at a mysterious place called Promised Island. At the request of his father, Wataru is whisked away to the island, and before he can settle in, a dozen of cute and charming girls start to flock him and claim to be his younger sisters. As Wataru gets closer to his newfound siblings, a deeper mystery as to why they were sent to the island comes to play. <br><br>
(Source: Anime News Network)