Harry Potter: Ero World - Chapter 123: A night once forgotten! Part-1

A man who was once called the world’s strongest agent ended up becoming a teacher after his retirement, to train a new generation of agents. After many years of training his disciples, he was killed at the age of 60 by a secret organization’s ruse and was reincarnated in another world with his memories intact. Though he was surprised by the existence of magic and the strange species in that world, he quickly adapted to his condition as a newborn and took advantage of it. He acquired special magic and gained a massive amount of strength thanks to his rigorous discipline, in order to reach his goal: Resume his career as a teacher which he left halfway through in his previous life. This is the story of a man, who, based on the memories and the experiences of his previous life, became a teacher who travels through the world with his students.

An immortal cultivator is murdered by her master and finds herself reborn in the strange world of One Piece. She hardens her resolve to once more tread the path of cultivation, only to find it won't be as easy as she thought.

Breasts are NOT supposed to spontaneously grow for no reason.Women's personalities do NOT flip on their heads without warning. These are two things Tsunade believes wholeheartedly.Until Hinata's embarrassingly large girls begin to expand even bigger than before. Heralding her devolution from a sweet and innocent young lady into a foul-mouthed slut with tits like weather balloons. Tsunade intends to find out why.

He became a teacher at the best magic academy in the empire.
….For being mistaken for someone else.