Mitsuki and Masaru only make their debuts after the Hideout Raid, when Eraserhead makes his stops at Class 1-A’s houses to gain confirmation for the students to continue attending U.A, and to stay in the 1-A Heights dorms.
The family is shown to have a rather intense- and tiring dynamic, according not only to Eraserhead, but the ever-so-patient All Might as well. At one point, the family was described to be unstable, although it is unclear if this is really true, due to Masaru and Mitsuki not making any appearances past their debut, and Katsuki not speaking about his home-life often, similar to the rest of his classmates.
Katsuki seems to have gotten all but few attributes from his mother, from her spikey blonde hair, to her sharp red eyes- the only features he seems to have gotten from Masaru are a slight tan in his skin, and a slightly darker hair tone than Mitsuki.
Mitsuki’s quirk is Glycerin, which she secretes from the pores of her face, while Masaru’s is Oxidizing Sweat, which sweats out like typical sweat, but can create a (weak) explosion when he pounds his hands together. While Katsuki’s Explosion seems to fare heavily from Masaru, it seems the chemical properties of Mitsuki’s Glycerin is what gave him the explosive kick for Katsuki to be as powerful as he is.
Mitsuki & Katsuki
Katsuki and Mitsuki are almost exactly alike, in both looks- and personality. Their explosive personalities, and unwillingness to back down lead to clashes between them, although it seems that Masaru makes attempts to break these up before they can become uncivil. Mitsuki seems to be very aware of her son’s inflated ego, and the praise that led to it, and hopes to see U.A take care of Katsuki, and help him reach his truest potential. Katsuki addresses his mom as “Old hag”, which evidently, due to her love of her youthful beauty, (given to her by her Glycerin quirk) annoys Mitsuki, so she calls Katsuki “Brat” in turn.
Mitsuki & Masaru
Masaru once had a desire to become a hero, but ended up finding his passion in the field of design, where he met Mitsuki. His section on his and his wife’s shared omake page says that once the two of them met, Mitsuki came onto him hard, and eventually won his heart. Additionally, Masaru has been stated to “have a thing” for strong, dominating women like Mitsuki.
Masaru & Katsuki
Katsuki and Masaru are not shown interacting too heavily, as Masaru’s docile nature is easily overrun by his wife (and son’s) temper(s). However, it seems that the two get along fairly well when Katsuki isn’t previously “triggered”. When Katsuki begins to lash out, despite being nervous to, Masaru does make an attempt to calm his son. Katsuki addresses his father as “Old man”, although Masaru simply addresses him by his name.
A few fans have speculated that (part of) the reason Katsuki pulls such awful facial expressions is that he thinks he looks too much like his mother. Aside from their obvious similarities, in canon, Mitsuki is regarded as pretty and youthful for her age, whereas Katsuki was labelled an Ikemen (good-looking guy) in a sketch done by the creator. Mitsuki's willingness to smile and be polite makes her good looks shine through. On the other hand, Katsuki's prettiness only shows when he's not sneering. Hence, the theory that he intentionally does this.
In regards to the family dynamic, there have been a mixed bag of reactions within the MHA/BNHA fandom. Due to Mitsuki calling Katsuki “weak” for being kidnapped, and even smacking him, Mitsuki is often written off as abusive. This is further exacerbated by Katsuki's evident fear of being weak, as well as a scene in the Remedial Course Arc where Katsuki insists on getting rough with the rambunctious children, because, "That's how [he] was raised." Masaru is also seen as neglectful or enabling as a result of his lack of interference. However, due to the lack of screen-time and other nuances, it is difficult to fully determine whether or not this is the regular or intended dynamic of the family. Those that disagree with the abuse narrative often point to cultural differences in methods of discipline, the comedic tone of the scene (in contrast to the tone used for other abusive families in the series) and/or Katsuki's penchant for exaggerating things. In the family scene, Mitsuki is shown to display a basic understanding of Katsuki's flaws, and she and Masaru believe UA High School will allow him to overcome them. This makes it obvious that they love and want what's best for him. As a result, many people believe that Mitsuki and Masaru's hearts are in the right place, but they are unintentionally doing more harm than good by exacerbating Katsuki's inferiority while trying to fix his superiority complex. This would not rid them of guilt but instead put them in a position to do better once they recognize their wrongdoing.
Fans that see the family’s dynamic in a more positive light tend to view the Bakugou parents as a support system for Katsuki. The dynamic between mother and son is still rough but not something that either takes to heart. Mitsuki’s spitfire attitude also makes her fiercely protective of Katsuki, while ever-docile Masaru is more nurturing and silently proud.
- Katsuki's name (勝己) is a combination of the kanji for Masaru (勝) and the last character in Mitsuki (光己). This may reference the fact that Katsuki is an almost perfect combination of his parents, physically and power-wise.
- His basic features heavily resemble Mitsuki (blond hair and red eyes), but he is neither as pale as her nor as dark as his father. Instead, he is somewhere in between.
- Katsuki's Quirk, Explosion, is an ideal combination of his father's "oxidizing sweat" (which allows for small explosions) and his mother's "glycerin". This allows Katsuki to secrete nitroglycerin-like sweat which he can ignite on command.
- The Bakugous' ability to create the "perfect offspring" in one child makes them a narrative foil to the Todoroki family. This is also apparent in the contrast between Masaru and Enji. While Masaru gave up on being a hero, Enji strove to become one and took on the hero name Endeavor. To endeavor is to "try hard to achieve a goal". One of Endeavor's goals was to make a child with the perfect combination of his and his wife's Quirks. Unlike Masaru, it took him four tries to achieve this.
- Both families are dysfunctional but the Bakugous are given less prominence and are presented in a more comedic light.
- Masaru's name means "win, victory" (勝 katsu/masaru) and Mitsuki's name means "light, gleam, shine" (光 mitsu) and "self" (己 ki). Therefore, Katsuki's name roughly translates to "win myself", or in other words, "to be ambitious and surpass oneself."
- Katsuki's name may reference his narrative journey to overcome his weaknesses.