Inconvenient Convenience Store

There’s a convenience store that feels uncomfortable but somehow keeps drawing you in. One day, a new night-shift part-timer appears at the small convenience store -- his rugged looks fill everyone with unease, but soon he brings about a refreshing change to this small convenience store. He helps not only his coworkers but also customers, resolving their worries and troubles. Who is this mysterious night-shift part-timer? (Source: WEBTOON)