I'm looking for a manga that I read years ago, but can't remember the name of. Here's what I can remember about it:

-The main character was a young woman (about 19 or 20) who had just become either a teacher or teaching assistant.
-The manga starts off with her posting a picture of herself wearing a high school uniform. She meets a guy as a result. She doesn't tell him she's not actually a high schooler.
-She starts work only to see the guy she met before is one of her students.
-At some point, her ex-boyfriend comes back into the picture.
-Another male student seems to develop feelings for her.
-She seems to obsess on the idea of having sex in a high school uniform.
-Its not a hentai!
-Its not Sekai wa Bokura no Tamen.
-There was a chapter where the girl, the male student who is now her boyfriend, and the other male student rival are taking some kind of a cooking class.

I've been searching for days, so hopefully someone can help! Thanks!