Boku no Heya ga Dungeon no Kyuukeijo ni Natteshimatta Ken: Houkago no Isekai Bouken-bu  

Boku no Heya ga Dungeon no Kyuukeijo ni Natteshimatta Ken: Houkago no Isekai Boukenbu, My Room Is a Dungeon Rest Stop: Afterschool Isekai Adventure Club, 僕の部屋がダンジョンの休憩所になってしまった件　放課後の異世界冒険部

After my parents disappeared, I, Tooru Suzuki, found myself without a stable home. As a result, I ended up working as the caretaker for a school dormitory located in Tachikawa. The building was old and needed repairs, and the students who lived there were all peculiar individuals. There were even rumors that the place was haunted by ghosts. However, to my surprise, it turned out that this dormitory was connected to another world! Despite not having any friends at school, I could always head down to the dungeon after classes to fight monsters and improve my skills. During these adventures, I made friends with a slime, a female knight, and even a sorceress. So began my daily routine of engaging in after-school activities in another world!