Katakoi Drops 

Sanae, positive minded and super beautiful, always popular among men, and Taishi who is the ace of Track&Field casually gentle with girls and popular among girls. Ordinary girl Yui, is proud to be both of their childhood friend. Yui had feelings for Taishi since a while back but kept to her heart since she didn't want to break the relationship that the 3 had. One day, Sanae told Yui "I love Taishi" Yui promise's Sanae that she will cheer them on and....?! (Source: Chibi Manga) Included one-shots: Suki dake ja Wakaranai, Darling I Love You