I Love Big Brother So Much!
A chain of initially unexplained events leads Wataru to meet his eight other sisters.
Aired 12/04/2001EP 2 - I Love Big Brother So Much!
2001
Sister Princess
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.
(Source: Anime News Network)