This is a long chapter, but it is very attractive. Evening face, refers to a pure flower shown in the story, also refers to the mysterious lady, which is the main character of this story. As the name shown, evening indicates the end of the day. It also indicates the end of the mysterious lady's life and the love between Genji and her.
Once, Genji goes to visit his old nurse, a procedure which involves a great deal of weeping by everyone, plus much commenting on how utterly perfect, gorgeous, and wonderful Genji is. Genji is attracted by the perfect foreheads of women in the neighborhood, and he exchanges poems on a fan with a mysterious lady. Later, Genji runs off with the mysterious lady, who seems sweet and shy. Actually, she's not all that passive, because since Genji refuses to tell her his name, she refuses to tell him hers. So they are having this nice affair, when suddenly this mysterious lady died.
The death of the mysterious lady drives Genji to distraction. Genji makes sure she gets a proper funeral, then he collapses from the stress and grief, and is ill for quite some time.
The puerility, simplicity, and early death of this young mysterious lady make her looks like a spirit in the story. She is such a pure lady without jealous, veteran, and vicious personalities. I think that's the reason why Genji loves her, and misses her even though she died for years.