Katainaka no Ossan, Kensei ni Naru

Beryl Gardenant is a man who runs a small swordsmanship dojo in a rural village. The glory he dreamed of as a swordsman is nowhere to be found. He spends his days calling himself a dull old man. "Will I continue to grow old quietly like this?" One day, one of his former students, Aleutia, who had risen to the rank of Knight Commander of the Kingdom at a young age, visited him. "I have recommended you as a special instructor with the knight order." "......what??" He has cultivated his swordsmanship over the years to the point where no one can match him, and his successes have earned him a reputation in the capital as a backwater swordmaster. "Isn't that title uncool?"