 If you liked
Boukensha ni Naritai to Miyako ni Deteitta Musume ga S-Rank ni Natteta
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 ...then you might like
Katainaka no Ossan, Kensei ni Naru
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In both series the protagonist is a middle-aged man who is good at swordsmanship. They both think they are weak but are actually strong. They both trained up girl(s) who rose to become famous in the big city, who bluff about how strong their master is and puts the protagonist in a tough spot.