If you're looking for manga similar to Yuusha no Deban Nee kara!! (Light Novel), you might like these titles.
Toushirou is a barista working in Tokyo, which has been isolated after it transformed into another realm. One day a mysterious girl who looks exactly like his first love Fleu, who he had been searching continuously for, appears in front of him. However, perhaps because of the fact that she lost her memories, she claims to be Flika, and completely unlike Fleu, has an extremely free spirited personality!?As someone who also takes up odd jobs, he accepted the request to look for her brother Chris, but in the process discovers the truth behind the identity of the young girl and the Other World. In order to take back what this young man lost and to retrieve the young girl’s lost memories, the two head towards the center of the Other World!