Trivia / No Matter How I Look at It, It's You Guys' Fault I'm Not Popular!
Actor Allusion: In chapter 56, Tomoko gets to school late after she catches an episode of My Little Pony: Friendship Is Magic on TV and gets drawn in. ("Who the hell schedules a cartoon like that in such an early time slot? Even elementary schoolers couldn't watch that without missing school!") The show isn't named, but Tomoko's TV shows an image of Rainbow Dash — who is voiced in the dub by Tomoko's actress, Izumi Kitta.
Tomoko's character design was originally meant to be taller, with smaller sanpaku eyes, however, the publisher asked for a cuter design. Arguably a positive example, since making Tomoko scrawnier and with oversized eyes ended up complimenting her characterization by making her look sickly and stunted
Yuu-chan wasn't originally a part of the manga, however the publishers thought it was too depressing for Tomoko to have no friends. Again, this was arguably a positive example, as Yuu has turned into a character foil who amplifies Tomoko's social maladjustment
Fan Nickname: It might actually be easier to list characters who don't have some sort of a nickname. If a character shows up at least somewhat prominently rest assured that the fans will bestow a nickname on them and make liberal use of it.
/v/'s nickname for Tomoko is "Spaghetti-tan", because of their meme about spaghetti leaking out of their pockets during socially awkward situations, seemingly for no other reason than to make the situation even more awkward and embarrassing for them. Turns into an Ascended Meme when, as a thank-you to foreign audiences, Tanigawa drew a picture of Tomoko actually eating spaghetti.
World Three, the primary scanlation group for the series, affectionately gave the manga the project title "loser girl."
"Slut-chan" for Yuu, because, in Tomoko's eyes, girls more socially adept than she is are "bitches" or "sluts".
Yoshida's unnamed friend is "Heroin-chan" because of her relatively large eyes and eye bags. She's also called "Meth-chan" for the same reason. Yoshida's other friend Rena tends to be called "Dark-chan" due to most of her face being shadowed over by her hat.
"Komi-something" for Kotomi Komiyama after Tomoko's ignorance to properly saying her name.
Ucchi is usually referred to as "Emoji", due to her simple but expressive face.
Asuka Katou was referred to as "Makeup-chan" for the longest time due her penchant of applying makeup on Tomoko, and because it took a while for the manga to even attach a name to her face. The Japanese fandom on the other hand come to call her "Katou-mama", after Tomoko sarcastically called her the "class mom" during the 2nd-year Christmas party.
Tomoko's social circle at high school is affectionately referred to as the "Reject Posse" due to initially consisting of loner girls who couldn't find a group for the field trip to Kyoto, though it's since expanded to include everyone Tomoko regularly interacts with at school. It consists mainly of Tomoko, Yuri, Yoshida, and Mako, with Ucchi and Hina being more tenuous additions.
Speaking of Tomoko's new friends, Masaki Yoshida is often referred to as the "Pure Deliquent" due to her tough-girl attitude coexisting peacefully with her love of all things cute. The trip to Disneyland in Chapter 126 highlights this, as she's the only other member of the group after Mako who's genuinely enjoying herself.
What Could Have Been: According to the Japanese Wikipedia at least, the authors originally planned Tomoko not to have a single friend. The editor found this premise too depressing and asked the authors to introduce a friend for Tomoko, which is why Yuu was created. Also, Tomoko's design (see Executive Meddling).