"All-Rounder" by Totoki Naoko

The story takes place in one of the convenience stores that blanket Japan. The protagonist is a fourth-year college student working at a store in Tokyo. He's in the throes of job hunting but things aren't going well. He lacks self-confidence and feels stuck. Lots of international students work part-time at the store. Ryo's monotonous days are spent on menial tasks running the store and teaching his international-student coworkers about their jobs. Then, an unexpected event puts the store in the media spotlight and mayhem ensues. In the aftermath, Ryo's coworker makes a comment that puts the wind back in his sails.