Eijiro Kirishima and Katsuki Bakugo
Eijiro and Katsuki are close friends, shown to hang out often when their classmates immediately turn to Eijiro to find out Katsuki's whereabouts. Eijirou is the only classmate Katsuki views as an equal, and he often calls him by his real name instead of the the nickname "Shitty hair". Eijirou is the closest to Bakugo as seen he is the only one who Bakugo mostly talks to.
Eijiro Kirishima and Mina Ashido
Eijiro and Mina don’t interact very often, but get along quite well when they do. They have a shared past, as they attended the same middle school, and Eijiro often found himself feeling jealous of Mina’s courage and strength. They have kind, excitable personalities, the reason they get along so nicely. Mina was inspired by Eijiro’s "Unbreakable" super move resulting in her creating "Acid Man".
Denki Kaminari and Katsuki Bakugo
While Denki and Katsuki didn't initially get along- Katsuki finding Denki to be a particularly annoying extra, and Denki finding him rude and a bully- their relationship has developed to a point where they're somewhat friendly acquaintances. Denki often teases and provokes Katsuki, occasionally going a little too far and being yelled at by Katsuki.
Denki Kaminari and Mina Ashido
Denki and Mina are often paired together within the series, implying they are close friends and hang out together often. When Mina is excitedly talking about being on a hero team with a few of her other classmates, Denki asks, "What about me?" and Mina bluntly replies, "No." This seems to an ironic statement though, as they are seen brushing their teeth together only a few panels later, one of many instances of them interacting casually. They've apparently bonded over being the two lowest ranking students in the class, in the Ultra Analysis stats, they both have 1/6 in intelligence, causing them to be paired up quite a lot in exams by teachers. Together, they fail their first-term practical exam, when they underestimate their opponent's capabilities and fall into his trap.
Denki Kaminari and Hanta Sero
Denki and Hanta share a close friendship. They often interact, making jokes with one another, and seem to like each other's company well enough. They are seen multiple times together, such as in the seating during the Sports Festival Arc, packing up for the Training Camp Arc, and generally when the class is together.
Eijiro Kirishima and Denki Kaminari
Within the classroom, Kirishima sits behind Kaminari, and they are shown talking on more than one occasion. After Kirishima's hero debut where he defeats his first villain, Kaminari is first to congratulate him, and then proudly showing everyone else his friend's accomplishments.
In the provisional licensing exam, Katsuki, Eijirou and Denki teamed up, taking down Seiji Shishikura. All of them eventually passed the exam. They demonstrated good teamwork, and mutual faith in each other.
Katsuki does not refer to anyone by their name except for Eijiro; instead, he has mean nicknames for all of them. Mina is "raccoon eyes" due to her large black sclera, Denki is "dunce face" because of the after-effects of his quirk and Hanta is "soy sauce" or "plain face" in the dub. Katsuki seems to consider calling someone their real name a sign of respect; thus why he only does this with Eijiro.
While Katsuki is slowly growing as a character, it is important to note that he still doesn't see anyone other than Eijiro as a true equal. This suggests that he can't really be considered friends with anyone else just yet, and therefore Bakusquad can't be considered fully canon. Their comradery has a ways to go before they can be considered a genuine friend group.
While their status as an exclusive friend-group is a fanon concept, many of their individual friendships are strongly established, making their canon-status semi-canon.
In fanon interactions, the Bakusquad are shown to be an inseparable bunch who have the tendency to fall into hijinks and shenanigans of any sort. Katsuki is shown to care aggressively for his friends, becoming annoyed when they do dangerous things, but masking his concern with disdain. A popular trope used within fans is Katsuki fondly referring to the group as “his idiots”
Denki and Hanta are seen as the “members” of the group, thanks to their already dim-witted, smiley personalities and ridiculous jokes. Mina sometimes falls into this category as well, but is more often than not ends up as a type of “love-guru” for the others, while not being able to catch a relationship herself!
Eijiro is portrayed as extremely protective of his buddies, a trait carried over from canon. He usually makes sure to keep everyone smiling, and will stop at no extent if someone tries otherwise. Katsuki is recognized as the group’s “leader”, as the name “BakuSquad” suggests. He takes on the role of mom-friend in some cases, as not to allow his friends to get hurt. The mom-friend trope is sometimes taken over by Hanta, however.
Fanon Bakusquad usually has the gang as a group of "members", and fanworks for them are often silly and shit-posting in nature. The tone of fanworks is usually light-hearted and humorous, a contrast to the more angsty side of the greater MHA fandom.
A big part of fanon Bakusquad is how Katsuki really sees the other members. While in canon, he's often dismissive of them, and thinks himself superior, fanon Bakusquad explores the idea of Katsuki gradually beginning to see them as equals and friends in their own right.
While in the anime/manga they are usually shown interacting one on one, Bakusquad fanon interactions tend to place them all together, with the gang meeting up for meal times, having sleepovers or movie nights, and regularly going places together.
The Bakusquad is commonly thought to be the anti-Dekusquad, another friend group between Tsuyu Asui, Tenya Iida, Izuku Midoriya, Shoto Todoroki and Ochako Uraraka. There's no canon rivalry between the two groups, but the rivalry between their namesakes Bakugou and Deku is enough for the fandom to support the idea. They are opposites in the tone of their friendships; the Bakusquad is loud and chaotic, the Dekusquad is more calm and controlled.
While Bakusquad is not a romantic pairing, it is frequently accompanied by the slash ship of KiriBaku, between two of it's members. Bakusquad is often a side pairing in KiriBaku fanworks, with the squad being supportive of or even encouraging them to pursue the relationship.
- On growing occasion, Kyoka is considered a part of the BakuSquad due to the friendship she melded with Katsuki during the U.A Concert, and her previous closeness with Denki (this occasionally occurs with Fumikage as well). Similarly, and very rarely, Ochako will added as well thanks to her friendship with Mina, and the popular (friendship) dynamic she is portrayed to have with Katsuki in fanon.
- Eijiro is considered as the “founder” of the BakuSquad, as he is the one to originally reach out to, and break Katsuki out of his shell.