Seitenkan (The Sex Change) -You Can Cum Inside Me! by Dieselmine eng, jap

There were no changes in Akira's life.
Every day, he defended his little sister from a drunken father.
A school of "strict" regime in which only boys were taught (only strict male teachers taught) *.
In his head it only flew: "I hate horseradish life!".
But after one accident, everything changed, and our hero woke up as a girl.