One-Shots

One volume from Change H Pink, an anthology series of short non-hentai (though possibly ecchi) stories focusing on transgender, crossdressing, and sexual transformation -- published by the editors of Shounen Gahosha's Monthly Young King under the TS Comics imprint.

Boy Meets Girl, Girl Meets Boy is the lead off story, a one-shot by Ryuta Amazume (author of Nana to Kaoru) that describes the issues two students face as they struggle with "post-pubertal gender change disorder" -- Yu, a boy, begins to grow breasts, and Junko, a girl, grows a penis. How do they deal with the changes sweeping their bodies?

(taken from Mangahelpers) 

Ayaka has always been reserved and guarded, afraid to open up her heart. Are chocolates the key to her heart and love? 

During his free time in Okinawa, Ken is suddenly forced to coupe up with a girl.  

Fuyou loves her brother. Actually, he isn't really her brother, so can she love him? 

Futagami Sousuke, 14 years old, is a normal student, wishing to live a normal life. But everything changes the day he sees a doppelganger of himself in his house.
Since then, the girl he has a crush on, Amane, will introduce him to another side of his world he had no idea about, and it won't be anymore the dear peaceful days for Futagami.