Kodomo no Omocha & Gakuen Alice are quite similar in many ways. The main character (Sana in KnO & Mikan in GA) is a super-hyper little girl who's maybe a little dumb at times, but still seems to make friends with everyone. Enter the troubled boy (Hayama in KnO & Natsume in GA). Girl & boy start out mortal enemies, but somehow end up being the only ones who can really understand each other. Girl breaks through boy's tough shell, and they live happily ever after... well, not quite. Like most school couples, they seem to have a hard time realizing their own feelings. Troubles abound, untrustworthy teachers interfere, and confusions about "who likes who" arise. Kodomo no Omocha is quite a bit longer than Gakuen Alice, so there are more twists and turns. But the heart of the stories are very similar, so if you liked Kodomo no Omocha, you should definitely check out Gakuen Alice.