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

Kousuke Kurono was an Avenger. After being raped, his beloved little sister was left out in the cold and froze to death. From the time he was 13-years old, Kousuke made use of any possible means in order to exact his revenge. 5 years had passed, he achieved his revenge, but having lived solely for the sake of revenge, at the moment his revenge came to fruition, afterwards he couldn't muster up the willpower to live on. That's why, with the same knife he used to kill the culprits, he slit his own throat. However, he then heard a voice; "Is that not wasteful?" When he came to, he found not his home, his country, nor his world——It was another world. ___ * [Japanese Web Novel](https://ncode.syosetu.com/n7225df/)

A dungeon with seven levels that can grant all human desires. For those who want to explore the dungeon, a license is needed. Therefore, many enter training schools. At the school there is a young teacher with a bad reputation named Dill, then he meets a girl who wants to reach the eighth level and only Dill has ever gotten there.