Funny: No Matter How I Look at It, It's You Guys' Fault I'm Not Popular aka: Its Not My Fault Im Not Popular
Upon working up the courage to face the cockroach everyone else is afraid of, Tomoko squishes it without remorse. And happily goes to clean her shoe as she imagines what her classmates think of her. Good news, they're not ignoring her anymore. Bad news, they now think of her as the weird quiet girl who crushes anything that annoys her, even something that has the rest of the class up and running in the opposite direction. It is both sad, and completely hilarious.
In the spinoff, "It's not my fault my friend is not popular" during one of their earlier meetings Yuu hears Tomoko talking about "getting hard" and is confused by what it could mean. She then reads it up in a book and is confused by the word for the male genital, which she then looks up too and gets more confused. The whole scene makes it look like Yuu is very naive and has no clue about sex. Until the end where it's revealed she knew what it was the whole time but merely knew the vulgar term for it.
Kii-chan's expressions of anger are terrifyingly funny.
The ending of chapter 61, where Tomoko's attempt to act as the older cousin and give Kii a serious lecture gets undermined by her Implausible Deniability about the fact that she peed herself when Kii pulled a scary prank on her
In the spinoff: Tomoko gets a caterpillar on her head. Yuu tries to swipe it off with a broom but she swings too hard and squishes it. Instead of screaming, Tomoko spaces out and imagines she's a samurai, sword in hand.