My Room Has Become a Dungeon's Rest Area

There has to be a catch when a deluxe rental property is this cheap–and this one connects to a perilous dungeon in another world! Far from being dissuaded, Touru jumps at the chance to sign the lease, hoping to go from high school dropout to big-time adventurer. He soon encounters a stranded knight: a gorgeous young woman named Ria. Touru rescues her and takes her back to Earth, where she promptly mistakes him for a Great Sage, seeing normal things like running water for evidence of his powerful magic. Touru may dream of heroism, but first he has to figure out how to share an apartment with a cute girl from another world! (Source: Seven Seas Entertainment) *Note: Includes two extra chapters.*

After my parents disappeared, I, Tooru Suzuki, bounced around from place to place and ended up as a caretaker of a school dormitory in Tachikawa. The building is in disrepair, the student boarders are all weirdos, and of course, there are rumors about ghosts haunting it too. It turns out that believe it or not, the dorm is connected to another world! Although I don't have a single friend in class, I can always just go to the dungeon to slay monsters and level-up. There, I became friends with a slime, a female knight, and even a female sorcerer! Thus, I begins another day of after-school club activities in another world! (Source: Takeshobo, translated)

*Note: Includes an epilogue.*