Katainaka no Ossan, Kensei ni Naru ~Tada no Inaka no Kenjutsu Shihan datta no ni, Taiseishita Deshi-tachi ga Ore wo Hottekurenai Ken~

Beryl Gardernant, who ran a dojo in Reveris Kingdom, had come to terms with his physical limitations and had settled into a peaceful life in the countryside. All of that changed when Alexia, one of his former pupils, arrived to inform him that he had been selected as a special instructor in the national Knight Order. This sudden development completely upended Beryl’s life.
He was reunited with his former students – now powerful knights, skilled adventurers, and successful magicians – but was subsequently expelled from the dojo that had belonged to his family, marking an uncertain future for him.
While Beryl was appreciative of the respect that his former apprentices had for him, he remained humble due to his belief that he lacked substantial strength. What Beryl didn’t realize was that his former disciples recognized his exceptional talent – a talent that Beryl himself was completely unaware of. As he continued to gain recognition and establish himself in the world, he remained oblivious to his own immense potential.