Vacation Is Love
After a mishap involving Rinrin's submarine, Wataru and his sisters are marooned in an island with a very stylish beach house.
Aired 21/06/2001EP 12 - Vacation Is Love
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)