Mellow(1993)

I'll give you a real education! ♡

To lay low after messing around with a crime boss's daughter, Haijima Akira disguises himself as his sister at her high school teaching job. If he wants to keep his you-know-what off the chopping block, he has to navigate both modern womanhood and the cruelties of high school students — all without letting his masculine rage blow his cover.