Datenshi-chan wa Ganbarenai

Tsubasa, a second-year high school student, is left stranded when his family’s fitness gym suddenly goes under. His luck seems to turn around when Maria, the chairwoman of Angel Academy and a former regular at the gym, offers him a full scholarship and a new place to stay.
But not without a catch. Moving into the academy dorm, Tsubasa is tasked with looking after the seven girls he will be living together with—and Maria gives him one ironclad warning: if he lays a hand on any of them, he is out. 
Surrounded by a cast of alluring girls  who are anything but ordinary, Tsubasa soon finds himself caught in a storm of temptation, chaos, and one dangerously thrilling situation after another.

(Source: Pocket Magazine, translated)