There was one brick joke of sorts at the very beginning of the series after Zenkichi is made to join the student council by Medaka. He essentially is displeased with how the student councils black uniform looks on him and Medaka suggests he just wear his gym uniform under the blazier. He does so and instantly finds it cool. He wears it like that for the entirety of episode two, but instead of starting a fashion trend, as he intended, he just weirds people out.
In Chapter 37, the Student Council comes across a research facility full of animals that don'tfreak out at the sight of Medaka. She reacts like a kid in a zoo, forgetting the current situation so they can look at all the animals...but things get derailed when Kikaijima says she's not an animal person. Seeing Medaka go full Genki Girl as she tries to get Kikaijima to react (and her dry, cynical remarks about every one) is really something else — especially because, as it's pointed out, this is the first thing the two girls have disagreed on since becoming friends.
Expecially because Kikaijima's critique of the giraffe and elephant is "Oh, this is classic. A long neck and a long nose? What, did they run out of ideas or something?"
Nabeshima explains that she managed to survive Kumagawa's onslaught by playing dead. She thought everyone else did the same thing. They didn't.
Chapter 93: Zenkichi walks in on his mother and Kumagawa in a... interesting position.
Chapter 101: Kikaijima and her group go up a staircase labeled "C" and wonder what it stands for
Sukinasaki Saki suddenly stripping in the middle of a concert.
The next chapter, Kikaijima, while onstage, in a swimsuit, shouts out her feelings to Medaka, starting with:
Kikaijima: "Medaka is STUPID!" (thereby voicing out what the student population felt about Medaka generally)
Tsurubami's blasé reaction to getting beaten up by Medaka.
Chapter 146 has a truly hilarious revelation. All throughout the series, Zenkichi has wanted to confess his love to Medaka. He ultimately decides against doing so when he has the opportunity because he thinks it'd be selfish to deny Medaka all the wonders of life by immediately tying her down to him after setting her free of her messaiah complex. While Chapter 140 ends with Medaka kissing him and saying she's fallen for him, it was always possible this was just Medaka being Medaka and it had no meaning at all. Then comes chapter 146 and we learn she actually asked him to marry her when they first met. At age 2. Zenkichi, being just a little kid, says no, crushing her. Naturally that was long ago, so Zenkichi probably forgot, but Medaka never did. It's not that she hasn't been able to fall in love that's kept her from having relationships in the past. It's that she's always loved Zenkichi, and admits she felt lucky he let her be his friend, unaware he feels it's the other way around. This whole romantic subplot could've been resolved long ago if they could just talk about it.
Chapter 151: Zenkichi's epic rejection. Also counts as an awesome moment.
[Leave that stuff to the preschoolers!]
Ajimu leaves a Video Will of sorts for Kumagawa in the form of a fully physical but pre-recorded her. She correctly guesses at what point he would try to peek up her skirt and kicks him in the face.
Ajimu: I can't see you but I can more or less predict your actions, so I'll just throw a kick here for good measure. If it connects; hooray for me.
In the very last arc, Medaka leaves the academy out of her own free will. The characters organize a grand sendoff including just about every named character in the series. Zenkichi resolves to look forward as the Student Council President and at the next Entrance Ceremony Medaka returns as the new Academy Chairman. Zenkichi face-faults and everyone is shocked except for Kujira. A small text box points to her saying "she knew".
In episode 5 of Abnormal, Munakata's reasons for killing got even more ridiculous with each line
And the way he says it makes it even more hilarious.
Zenkichi's reaction to Munakata's spiked staff.
The presentation of the (substitute) suitors, and the disgusted reaction from Medaka and her group. They're such big perverts that they disgusted Kumagawa.
As they challenge Medaka's group, Ajimu offers to take on them alone. They threaten her, ready to do disgusting things once they beat her... And for once, Ajimu's usual Curb-Stomp Battle was incredibly hilarious.
