Starry☆Sky, Brothers Conflict Recommendations
The main heroine from both series meets 13 guys. They have fallen in love with her. Both series are reverse harem. One series is a full length series while the other is an ONA: the length of the series is 15 minutes episode
Both have lots of good-looking men, who like the same girl. Ema in Brothers Conflict is the only girl at her home and Tsukiko in Starry Sky is the only girl at school. Both girls are a little plain but kind and every boy likes them (lol).
One girl, the rest guys who like her, every guy gets his own episode etc.