From Chibi Manga:

Mitsuki has an unrequited love for her older brother, Takashi-chan, since seven years!! And Takashi-chan is a teacher in her school!! "let's take some distance", Mistuki said... she wanted to keep secret the fact that they knew each other.

But that secret will be the start of their love!!

From Shoujo Crusade & Eternal Heart:

Akabane loses a game of bridge and thus his feelings for their classmate, Satsuki is revealed by his friends. He denies it immediately but somehow she's attracted to him too?

Also contains:
Half a Year - Kimi to 6-gatsu
Kirai Kirai Mo?
Kimi ni Yell wo!
Kirai Kirai Mo? - Extra

From Shinnen and Shoujo Crusade:

Bittersweet stories that make your heart race in a painful but happy way. A compilation of stories about one-sided love that will have your 100% sympathy.

Contains 5 short stories:
- Make Sweet
- Sugar Baby Love
- Meganegoshi no Kimi
- Haru, Urara
- Make Sweet - valentine special