"Akutou Danshi Collection" ( "Boy Rascals") by Kurumatani Haruko 1 volume
Suzuno switched schools and decided to stay at the campus dormitory to help out her family. To stop the demolition she becomes the dorm manager of unruly boys that made the place infamous as "City of Crime". Her strength will be tested to it's limits.
It's unconfirmed if it's a reverse harem because only few of the characters were named (2 more chapters to go). The romance feels rushed, without the build up and it it would have been better if it's ecchi instead of smutty.