I Got Turned into a Big Titty Female Teacher by My Psychopath Childhood Friend! ~He Rewrote My Past and Has Sex with Me as He Pleases!~

Tsubasa is a new male teacher who just reunited with his old playboy childhood friend Tatsuya. Tsubasa tries to set him straight, but Tatsuya uses some kind of magic to turn Tsubasa into a young and attractive woman...! Totally bewildered by the turn of events, Tsubasa is helpless to fend off Tatsuya. Thus begins 'her' sexual training... Tsubasa's body, mind... and even memory will all succumb to Tatsuya's technique in no time at all. (Source: DLsite)