Synopsis: Mouto wa Kanojo ni Deki Nai no ni

All of the strongest have been trained by the "Mentor". A kind-hearted young man named Haru resides in a dilapidated church on the outskirts of a frontier city, but his true identity is the legendary "mentor" whose students' names are well-known across the entire continent. The next individual he aims to guide is Rebecca, a mid-rank adventurer whose development has stagnated. How will Haru bring out the hidden potential of a girl who has lost faith in herself!?