She is first seen in Chapter 1, after Yuzu returns home after her first day at her new school. She asks Yuzu why she took so long to return home and Yuzu, apologizing, asks if her new father is already home. She cheerfully says "he left to see how is the other side of Earth" and won't be back for some time, also noting that he's the "impulsive type" as if it was cute. Yuzu, weirded out, asks if her mother is happy at the moment. Her mother gives her a positive answer, saying that Yuzu and her husband's daughter are with her, and that having two daughters makes her happy. Seeing Yuzu's confusion, she tells Yuzu that from now on has a younger sister, at which moment Mei enters the room. She's surprised that Mei and Yuzu already know each other. After Mei introduces herself, she tells Mei she doesn't have to be so formal, as they're now family, and says she hopes Yuzu and Mei can get along. She also mentions that Yuzu's birthday comes before Mei's, so which makes the older sister.
After learning about Yuzu's fan from Mei (much to Yuzu's chagrin), Yuzu's mother tells her she now has to be an example to her fan and says it's time for Yuzu to dye her hair back to its natural color. She then explains to Mei that Yuzu dyed her hair because people said she didn't look like her father, but Yuzu says that was when she was a kid, and now she dyes her hair because she likes it.
After seeing Yuzu with black hair, she starts laughing, despite being the one to tell Yuzu to dye her hair, and says Yuzu looks just like she did when she was younger.
One day, Yuzu's mother notes that Yuzu is late, so she invites Mei to read Shō's letter her. Afterwards, Mei asks her what is it that she likes about Shō. Yuzu's mother tells her about how he shoulders all problems on himself, which makes her want to support him She then asks about Mei, saying that she must be asking this because she wants advice on love, but Mei, embarrassed, says she's not sure.