Keiko gets too close to Touga and Nanami kicks her out of her Girl Posse and seeks to destroy her life. This sends Keiko to the Black Rose Seminar.
"Troublesome Insects" provides examples of:
- All Love Is Unrequited: Keiko's love for Touga surely is.
- Can't Get Away with Nuthin': When Keiko decides to take what could be her only chance of getting close to Touga by sharing her umbrella with him, Nanami quickly finds out and punishes her for it.
- Cinderella Plot: In this episode Keiko follows this trope to the point of parody, with Nanami filling the role of the evil stepmother. As Keiko gets close to Touga at last, she switches roles with Nanami, starting to humiliate her. To crown the subversion, Keiko ends up beaten and "princeless".
- Comically Missing the Point: In the day after the duel with Keiko, after seeing that she's back into Nanami's group, Utena comments to Anthy that she "doesn't get it". Recalling that Utena didn't know Keiko's name until the previous day, Anthy reminds her that the girl with the pigtails is Keiko, the girl with the shoulder length hair that curls outwards is Aiko and the girl whose hair curls in around her cheeks is Yuko. Utena clarifies that what she doesn't get is why Keiko went back to being friends with a girl she hates and with two girls that will choose to side with Nanami over her if it's convenient to them.
- Dances and Balls: Nanami organizes a ball at her home to cheer up Touga.
- A Day in the Limelight: This episode focus on Keiko, that for most of the series is little more than one of Nanami's lackeys.
- Disproportionate Retribution: Keiko offers her umbrella to Touga. Nanami's response? Remove her from all her clubs, positions of power at the school, and every other group she is involved with and basically ruin her life.
- False Friend: In this episode it's explored how Keiko really feels about Nanami. Deep down, Keiko hates Nanami but still sucks up to her so she can get closer to Touga.
- Foreshadowing: Anthy explains to Utena that the reason Keiko is willing to associate with Nanami, Aiko and Yuko despite how horribly they treated her is because it gets her closer to Touga. And that people are willing to do all kinds of horrible things if it's for someone they love.Anthy: You can keep lying to yourself as long as possible.
- Girl Posse: This trope gets deconstructed in this episode: it's shown that Keiko, Aiko and Yuko don't really care that much for Nanami, but pretend to be her friends so they could get closer to her brother Touga. And it's also shown, when Nanami kicks Keiko out of the group, that the three girls aren't that loyal to each other either, as Aiko and Yuko easily chose to side with Nanami instead of standing up for Keiko. The four girls always hang out with each other without there being any real feeling of friendship, and they will turn on each other if it will benefit them, yet, by the end of the episode, Keiko still rejoins the "friends" that rejected her before.
- Heel Realization: Sort of. During her duel with Utena, Keiko rants about how Nanami is trying to keep her from getting closer to Touga. It's at this point Keiko understands she has nothing to gain from killing Anthy. Instead, she should kill Nanami.Keiko: That's right. The real parasite... is Nanami.
- Jerkass Has a Point: Keiko is not necessarily a good person. She pretends to be Nanami's friend to get closer to Touga, will harass Anthy on a regular basis, and it's implied she'd also sell out Aiko and Yuko. It still doesn't change that she has the right to love anyone she wants, and she shouldn't have to let Nanami control her in order to be close to Touga, and that in the relationship that Nanami has with her Girl Posse, it's Alpha Bitch Nanami herself who's far more like a parasitic insect.
- Lonely Among People: Despite the episode barely focusing on him, it's events show how lonely Touga really is. Touga is wildly popular with many of the girls at Ohtori and has multiple girlfriends and sexual conquests, but he doesn't have any actual emotional connection to anyone outside of the Student Council, and even that is shaky due to how he treats everyone. This results in Keiko being the only person Mikage can find that has a strong enough connection to Touga to take his soul sword, a girl that only had about five minutes of actual conversation with him, and whose issues are more about Nanami that they are about Touga.
- Outside-Context Problem: Utena's regularly a dense person with an inability to read the room, but for once she's justifiably confused as Keiko rants throughout their duel about how much she hates Nanami. This is due to the fact that Utena has never associated with Keiko, never been involved in her life outside of seeing her as a lackey of Nanami, and didn't even know her name. So of course Utena would have no clue why Keiko has Touga's sword or why she wants Nanami dead.
- Umbrella of Togetherness: Keiko shares her umbrella with Touga, which enrages Nanami when she finds out.
- Worth It: A subtle example. While Mikage is annoyed at the failure, he was amused by Keiko calling the leader of her Girl Posse an insect.
