Daizai Dungeon Kyoushuujo no Hanmen Kyoushi: Hazure Gift no Annaijin ga Jitsu wa Saikyou no Tansakusha de Aru Koto o, Seito-tachi wa Mada Shiranai

[MangaDex]

 

[DreadKaiser]

Seems Generic AF

Teacher at magical school that has a horrid reputation despite being the most accomplished there, is surrounded by some hot girls...

where have I heard this premise before.