Haha, oh wow. Trying to back up your trolling with made-up facts? GTFO /a/sshole, just because the fucker is a newfag you don't have to troll him like that. All of a sudden he decides to download the crap that is Rosario and be disappointed since it isn't the show he wants to see.
As mentioned before, H2O. The character to the left is the loli-sister, and the character to the right is the main girl trying to seduce the sisters brother. And yes, as you've realized, it's a shoujo title.