It may be a just one of a few stories in the manga, I can't remember, but anyway, a gloomy uke transforms into a cheerful guy for the guy he likes (the seme is straight I believe) and if I recall correctly he shows up a the seme's work and asks him to be his boyfriend for like a month or 3 months or something. I can't even remember if I liked it, but it annoys me that I can't find it.
This is literally my favorite manga series ever. I love it so much. I wish we could get the next update.