Akari Iguchi

Akari Iguchi initially seems to be a one-off character, but later becomes an important supporting player.

She first shows up at the Kuroki household in Chapter 25, which becomes part of episode 3 of the anime, using a handout as a pretext to visit Tomo-kun (Tomoko's brother) at home while he's sick. However, he's sleeping so she postpones seeing him until he's better. Story-wise, her only purpose here is to make Tomoko miserable, because nobody ever comes to see her.

Akari (far right) visits the Kuroki household

Later in the manga, we see her a few times in the background, usually trying to get up the courage to talk to Tomo-kun. Generally, she's with the same friend who is always trying to encourage her. But Akari seems to be having trouble making her feelings known, and tends to chicken out.

In Tomoko's second year, Akari and Tomo-kun both enter Makuhari high school as first year students, and they both become more important to the ongoing story.

Tomoko first sees Akari at school while spying on her brother in his homeroom. This is not a significant appearance, but Tomoko continues to be irritated by how different her brother's situation is from her own loner status. Akari is still trying to win Tomo-kun's affection, but timidly. Her friend is always there to offer advice.

Later, Akari becomes a central figure in a farcical plot development involving mistaken identities.

In Chapter 83, Akari and her usual companion happen to visit Star Turry's, the same coffee shop frequented by Yuu-chan and her middle school friends, Tomoko and Komiyama. Komiyama is unnerved when she discovers that she has a rival for Tomo-kun's affections. After meeting Komiyama in the bathroom, Akari becomes confused by Komiyama's questioning, and assumes she was mistaken in thinking the other girl (Tomoko) was Tomo-kun's sister.

Komiyama doesn't correct the error, but instead tries to gain an advantage over Akari by warning her that Tomo-kun prefers "older women".

Thereafter, when Akari sees Tomoko together with her brother, she assumes incorrectly that Tomoko is Tomo-kun's upperclassman love interest, and that her gleeful teasing of Tomo-kun is actually flirting.

The situation comes to a head in Chapter 91, when Akari bumps into Tomoko and Komiyama in the hallway and invites them both to lunch. A panicky Komiyama, aware of her dangerous situation, continues trying to cover up her lie, insisting that Akari call Tomoko "Mokocchi-senpai" in order to block Tomoko from saying her family name out loud. But the jig seems to be up when Tomoko drags her unwilling brother to the table.

The farce works, and Chapter 91 was cheered by some fans as one of the funniest chapters yet.

The situation, however, seems to be far from resolved. So we expect to see Akari again in future chapters.