I remember some things, it's about a guy who dropped out of school because he had to work to support his home, so after a few years he decides to go for supplementary school . there He meets a girl who also dropped out of school, she dropped out of school because she was abused at home, they start to liking each other, he ends up saving her from being abused again.mc sister also go to supplementary school , mc is over 20 years of age .sorry for my bad english

It's Chuusotsu Worker kara Hajimeru Koukou Seikatsu, I think, though the MC is 18.

omg that was fast, thank you so much .