Asahi-kun wa, Namaiki Zakari no Otokonoko.

When I took off his dress and kissed him, I got excited down there...!? The first person I want to have sex with was a "crossdresser."
(Source: Coolmic)
Notes:
- All chapters were split into three parts in the original serialization and later combined in the volume release.
- Includes one extra chapter.