The quirks of My Hero Academia part 2

The quirks of My Hero Academia part 2

Today I will continue my examination of the quirks of My Hero Academia. If you missed The quriks of My Hero Academia part one you can find it here.

Shoto Todoroki- half-cold half hot


Shoto’s quirk is actually two quirks, and was another one that stuck out to me as there are some obvious downsides to his powers. The right side of his body can generate cold temperature, while the left side of his body can generate hot temperatures. The show states that he cannot use his cold powers for too long or he will give himself frostbite. Shoto uses his heat powers to help prevent this, and the show has yet to say what the downside to his heat based powers are. While My Hero Academia hasn’t said anything about this, science can make a few educated guesses about his quirks.

An elevated body temperature, or fever, is one of the human body’s responses to infection.

Normal body temperature 97.7–99.5 °F

Fever 99.5 or 100.9 °F

Hyperthermia 100.9 or 104.0 °F

Hyperpyrexia 104.0 or 105.8 °F

In Shoto’s case we will be looking at hyperpyrexia, or an extreme fever in layman’s terms. When body temperatures reach this level, they start to become life threatening. The reason for this is that the molecules that make up our body, specifically proteins, begin to fall apart at the high temperatures seen in hyperpyrexia. Essentially you are cooking your own body at those temperatures, and the highest body temperature than an individual survived was a fever of 115 F back in 1980. Knowing this I would speculate that Shoto would begin to have trouble as he raised his body temperature above 104F. Now he could use his cold quirk to mitigate things for a bit, similar to how his heat powers help to use his cold powers.

Hisashi Midoriya- Fire breath

There is no way that breathing out fire is natural, Mr. Anime Science, and fire breathing animals are the stuff of legend. Yes, you are indeed correct, but that doesn’t mean that by combining several different biological systems, you could potentially have someone or something breathe fire so hear me out. There are three things you will need in order to breathe fire:
1- Platinum- this particular element can catalyze an exothermic reaction between oxygen and hydrogen. In layman’s terms hydrogen and oxygen will react when in contact with platinum creating a fireball.
2- Hydrogen- can be created biologically by certain types of bacteria, which means nothing if it can’t be stored inside Hisashi’s body. This can be accomplished by an organ similar to the swim bladder of a fish. The swim bladder is a basically gas bag inside of the fish’s body and it is used to change the buoyancy of the fish so that it can float easily at different depths. Hisashi could have a similar organ connected to his lungs, and filled with hydrogen producing bacteria, so that he can breathe out hydrogen when needed. The secondary effect of this organ is that he could make his body lighter, as hydrogen gas is lighter than air. This could help him jump higher and farther.

3- Oxygen- this is the easiest one as he would be breathing oxygen in and out through his lungs. The reaction itself would take place in his mouth where a platinum pad could be located on the roof of his mouth or the back of his throat.
FYI- This is very similar to how it would work for Dragons.

Yu Takeyama- Gigantification


Sadly for Ms. Takeyama, I cannot give any possible explanation for how her quirk might actually work and hers is one that fails completely. Now there is a bit of confusion since one page on the My Hero Academia wiki states that she changes to 2062cm or 20.62 meters, and another states that she changes to 2062 meters or 2.062km. Either way the result is the same. The human body’s physiology has evolved over the millennia to work best within a certain size range and when an individual is outside of that range health problems tend to accumulate. This can be seen in people suffering from gigantism (7ft to 9ft); some of the areas affected include the muscular, skeletal, nervous, and cardiovascular system. In most cases these individuals are not as strong and robust as they appear.

“But what if she has physiology similar to dinosaurs as the largest ones were still bigger than she at 39.7 meters?” I can see where you are going with this and it is a good idea, but there is one thing that is often missed. In the late Cretaceous period where the Argentinosaurus, the largest dinosaur ever found, lived, the atmosphere was very different than what it was today. The atmospheric pressure of oxygen was around 28Kpa during the late Cretaceous period, which is significantly higher than the 21Kpa we currently have. The extra oxygen in the atmosphere allows for organisms to grow much larger than what they can currently. So, Yu would only be able to be in her larger form for a short period of time before suffering from a lack of oxygen.

Rikido Sato- sugar rush


Rikido is able to increase his strength by ingesting sugar, and the more sugar he eats, the stronger he gets. I can’t think of any biological reason for this to occur, but the downsides from his power, mainly the loss of cognitive function and sleepiness, can be. Essentially what Rikido is doing by eating larger amounts of sugar to fuel his power is giving himself hyperglycemia, or high blood sugar (200 milligrams of glucose per deciliter of blood). This is typically only seen in uncontrolled diabetics, and there are a number of side effects from having too much sugar in your blood including weakness, fatigue, and confusion. Thus, the side effects of sugar rush have some basis in the real world.

Toru Hagakure- transparency


There are actually several real-world animals that come close to mimicking Toru’s transparency quirk.

These animals are able to pull off their near total transparency due to the following three properties.
1- low absorption of light by the body tissues
2- a lack of dispersion of light as it passes through the body
3- minimal reflection of light when it hits the body
Now one thing you will notice is that Toru is completely transparent, while many of the animals shown previously are not 100% transparent. Realistically Toru should have this issue because while skin and loose connective tissue could be altered to be transparent, bone and muscle need to be dense in order to perform their functions and could not be completely transparent.

Tsuyu Asui- Frog form


While it might seem like Tsuya has multiple quirks it is just one quirk with several different abilities, but I will be focusing on her camouflage ability. While the chameleon is the most famous color changing animal, some frogs can also change their coloration in order to better blend in with their surroundings.(Which I did not know until I did the research for this article)

The color change is caused by a structure known as a chromatophore, which is a cell or group of cells that contain pigment and light reflecting molecules. These structures are not a one size fits all solution, as there are several subclasses based on the color that an individual chromatophore can create.
xanthophores (yellow)
erythrophores (red)
iridophores (reflective / iridescent)
leucophores (white)
melanophores (black/brown)
cyanophores (blue)

The chromatophores can be overlapped to improve the animal’s ability to create a variety of colors. Also, the chromatophores can be controlled by hormones or the nervous system. In Tsuyu’s case I think it is most likely nervous system control, which means she can change colors faster and have more control over the colors as well.


I hope you guys enjoyed this little foray into the quirks of My Hero Academia, and if I missed anything or I didn’t cover your favorite quirks let me know.

Update– I have now done a post for the quriks of one for all, and Eri.

Please leave any comments or questions in the comments section below.

3 thoughts on “The quirks of My Hero Academia part 2

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