Biased answer but it's not even a good manga, it's a GREAT FUCKING MANGA, the peak of human literature, even. Especially if you're looking for a story with a more slow-burning pacing and world-building, but masterfully-written plot, realistically written and interesting characters with great designs, GORGEOUS ART that evolves with each new chapter, MOVIE-LIKE fighting choreography, BEAUTIFUL panelling and composition and NO ROMANCE, ZERO FANSERVICE AND ABSOLUTELY NO SEXUALISATION, ESPECIALLY OF IT'S FEMALE CAST!! So give it a try.
So just like the short manga I stumbled upon that I forgot about the title the protagonist is a training freek at all time even in school he write by foot then by the summer he got some in short of a recommend by senpai of his in middle school to enter this high school a hidden school that all kind of martial arts, ninja, archer etc.
But it ended quickly hah so much potential.
Btw I just stumbled upon this in too but in YouTube short post.
Thank you for the reply.(◍•ᴗ•◍)
I'll follow you!(≧▽≦)

Is it a good manga? I see in YouTube japanese manga publisher acc but the current now comsect (๑•﹏•) it's like jujutsu again hah just for my peace of mind. ,◖⚆ᴥ⚆◗