 If you liked
Ai Kora
|
 ...then you might like
Ayu Mayu
|
These 2 manga series are similar in their main male character (the happy-go-lucky cum idiotic kind but serious in times of need) and that both feature love triangles between the guy and 2 close friends.
However, Ai Kora is more focused on fetishes while Ayu Maru is about two girls who might be the guy's brother, and the other possibly his gf (which is similar to Onegai Twins).