Jin-Ah is Jin-Woo's younger sister and basically the responsible one of the two. She's consistently at the top of her class academically—the kind of student who actually studies and gets the grades to show for it. The two of them are close, partly because they've only had each other for most of their lives.
Their family situation is rough. Their father got trapped in a gate, and their mother fell into a coma from Eternal Sleep, leaving Jin-Woo and Jin-Ah to fend for themselves. Because of that, Jin-Ah's always been anxious when Jin-Woo ends up hospitalized, and she's repeatedly asked him to quit hunting. She wants him to stay safe, which makes sense given everything they've already lost.
Content compiled by AnimeList.moe from publicly available sources.
