Jigoku Shoujo (Hell Girl) Season 4 Episode 6 Twill

Yui Aihara's boyfriend proposes to her, but there is a reason she can't be happy for it. A few years ago, her dad was managing a Chinese Restaurant, and while out on a delivery, he got involved with some drunk punks and ended up in a coma. Yui finally finds the person she has been looking for who holds the key to the truth of what happened.