Suki dake ja Wakaranai

From Cibi Manga:

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....?!

Includes one-shots:

From Shoujo Crusade:

Suki dake ja Wakaranai
Fujisaki fell in love at first sight with Nakamura-kun after he helped her out of an embarrassing situation. Fujisaki wants to be more lovey-dovey with Nakamura-kun however he is known for being the ‘antisocial king’!!!

Darling I Love You
Chiho has always loved Ryouhei but Ryouhei has never even shown a hint of liking her back. What does Chiho have to do to make him turn her way, even if it’s just a little…