Fantasy Sister!

Living in a country where every teen is totally immersed in games, Kang Eun Jung is the complete opposite. As someone who isn't really into games, she is often neglected by her friends. Due to how inconspicuous she has become, she is challenged by her brother to play a game, and that is how she, a fresh newbie, begins to experience various brand new feelings in the RPG world.

(Source: MangaDex)