 If you liked
Kodomo no Jikan
|
 ...then you might like
Himegoto: Juukyuusai no Seifuku
|
Both deal with destructive, co-dependent relationships and psychologically complicated characters with dark and cheerful sides and a lot of sexual molestation between friends and lovers. Zyuukyuusai no Seihuku is definitely the darker one of the two whereas Kodomo no Zikan is more lighthearted, and cuter.