The Wage of Angel of Death Is 300 Yen per Hour

"Well then, we'll employ you as a shinigami." The part time job I started doing is to clear away the regrets of the deceased with my classmate who's a beauty. The ones who pass away from this world with lingering regrets are given "lost time." The shinigami's job is to save the deceased and resolve their regrets though the wage is only 300 yen. What the protagonist discovers after getting involved with various different "deceased" is...