Theres this manga where The Mc is weak and not talented in swordmanship nor magic but his girlfriend keep accompanying him everyday but he didnt show any progression, suddenly one day he got defamed as cheater and his girlfriend broke up with him, he being bullied by entire school and he triand in a certain forest alone then meet a certain grandma who latter teach him a samurai like swordmanship. Whats the title again?

Theres this manga where The Mc is weak and not talented in swordmanship nor magic but his girlfriend keep accompanying him everyday but he didnt show any progression, suddenly one day he got defamed as cheater and his girlfriend broke up with him, he being bullied by entire school and he triand in a certain forest alone then meet a certain grandma who latter teach him a samurai like swordmanship. Whats the title again?