The MC is the sword teacher of the hero. He wants to become an adventurer (or knight, I dont remember since I've stopped reading long ago) but unable to do so since he lacked mana, an essential component in the world. He became the hero's sword teacher not because any major reason, just because he is their childhood friends. And it wasnt because he wanted to, or was forced to. It was all just a coincidence.

Time moves on and the MC still hasn't changed much, or any at all. His only change was the increase in proficiency in using the sword. But even this was inconsistent. Why? At one point, he was fighting with a sorcerer who hurled magic towards him and he shot it down with a throwing knife. Blah3 explanation on how he achieved that. But after that, he cant use it anymore, or more like the author may have forgotten about the setting. He is supposed to be unrivaled in the sword since even the so called sword saint is below him. But he is still weak as f*ck since he doesnt have magic? This frustrates me to no end. There was even a time he had been secretly assisted the hero where he lost against the enemy on horseback, WHILE using the sword with the enemy too using it. Like, the f*ck. How could you write about a whole story centering on him being the hero's sword teacher and showing he is proficient in the sword and throwing it out in the next.

at the start I was dissapointed because the MC was just 2 years older than the hero but I overlooked it because a boy even though is poor and an orphan still finds a way to teain himself to chase his dreams was interesting when the hero appeared and they developed a big brother and little sister relationship I tought it was sweet I could actually read this BUT after the timeskip it bored the hell out of me I desperately waited them to meet but nope still didn't get interesting. The hero praised him so much on before so I tought "maybe he is got stronger too he is her master after all the sparred all the time when they were kids she got strong enough to kill the demon lord" I had some expectations of him but BOY he was weak I know he is strong if we don't compare him to the hero but she overwhelmed him they he did manage to at les-ast stand hi ground against her a little bit but that was all you would've expected him to at least parry or dodge and try to attack her NOPE he could only just block patheticlly and don't get me started on the romance part HE DOESN'T EVEN RECOGNISE HER EVEN THOUGH HE REMEMBERS HER FACE AND HAIR COLOR