Convenient Miscarriage: Was pregnant with Jin's baby before marrying Youji, but it was a stillborn. Her mother wrote a rather confusing letter about it to her... Yuu found it and mistakenly thought it referred to him.
Cool Big Sis: To Miki, since she doesn't want to be pushy to her.
Spoiled Sweet: So much that in the anime, she singlehandedly finances her and Miki's trip to the USA, as a way to repay Miki's support that allowed her to go to Hiroshima and rekindle her relationship with Namura.
Throw the Dog a Bone: In the anime, he not only is more sympathetic and comes to support Ginta and Arimi, but he gets a girlfriend too.
Lampshaded by the author in the last volume omake: when talking about her characters, she said that she felt sad some of them weren't able to achieve happiness and she accompanied this with a drawing of Satoshi looking dejected and Rokutanda saying "At least I've got a girlfriend in the Anime"
Kick the Dog: Hiding Miki's medallion (or bracelet, in the manga), then giving it to Yuu and saying that she threw it away because she doesn't like him anymore. Yuu isn't fooled, but it still brings a huge rift between them.
Just a Kid: Miki thinks so. He's very unhappy about that.
Stage Mom: Both of his parents were this. He ran away from home because of their pressure on him. They get better.
Took a Level in Kindness: In the anime, when he re-appears long after his arc is over, he's much more mature and kinder.
Genre Savvy: Is very aware of her Unlucky Childhood Friend status and tries to make the best out of it. i.e. she never clings to Yuu and immediately tells Miki that she doesn't intend to break them up.
Ill Girl: Has a serious heart illness that almost kills her.
Dandere: He has an observant, and feminine outer personality but with a masculine, and hotblooded inner core.
Gay Guy Seeks Popular Jock: What people around him rumored his relationship with Brian was. But this was only the tip of the iceberg of him being actually a—
Guile Hero: Where his core motive of befriending Brian was to get close and befriend Jinny.
Genre Savvy: Like Anju, while his ultimate goal is to have Jinny become his girl, he's aware of Brian trying very hard to pursue her, while Jinny's trying to court Yuu, and that he himself might be a Hopeless Suitor to her. But he just opts to lay back and continue to observe the situation in hopes to have a chance, while at the same time actively befriends Anju to have a Birds of a Feather friend to talk with.
Mistaken for Gay: But being the Guile Hero that he is, he just went with the flow and semi-acted the part. Until Jinny suspected him dating Anju.
Kick the Dog: Telling Miki that she was Yuu's "other woman" as a prank, out of jealousy. This makes the already distressed Miki break up with Yuu in the airport, as she's too emotionally exhausted to handle a Long Distance Relationship.