Manga involving a high school and parasites

Question

I read a manga about 4 years ago and I lost it and I haven’t been able it forget about it ever since. I’ve been trying to find it but I’ve had no results. At the beginning of the story I’m pretty sure the male MC is getting attacked and someone saved him, the thing that was attacking them was a type of parasite. Anyway, the person who saved them is part of a group that saves people from the parasites and things like that. He then goes to a high school? Btw they live inside a wall or something? Anyway the person who saved him goes to his school, well actually a whole group of people, the ‘heroes’. Shows off this parasite that it a eyeball? I think it is a eyeball. But anyway he gets attacked by it? Well they end up in a bathroom and the parasite somehow gets defeated later on... by him? Anyway that’s where I was left off and I’m pretty upset I can’t find it. It this doesn’t make sense, I’m so very sorry. Please just help me find it? MC doesn’t really do anything important, just wishes to meet the person who saved him and became like them. think the MC mother died..

Answer 1

Maybe Parasyte . It has a manga, anime and live actions.
Pretty much these aliens parasites get inside humans and their goal is to get the brain to control their host. The MC notices the parasite and does not let it get to the brain and keeps it in his hand. He now has to live with this parasite. In school other humans infected with parasites come to fight others. Story short the mom's dies the dead mother hair style I don't recall a wall but is somewhat similar https://en.m.wikipedia.org/wiki/Parasyte

Answer 2

Is it perhaps Polarity...? I was looking for it myself and found your question while looking for my own answer.

From Manga Updates:

With the sudden outbreak of a deadly virus, humanity is thrown into chaos. The few who survive it are either transformed into horrible cannibalistic creatures called "Worms," or super-humans called "Anomalies." Haru, a young Anomaly student at New Seoul High School, dreams of joining the prestigious "ISO" - an organization formed to fight the war against this virus. But the future in store for him is nothing like he imagined...

It's pretty much exactly like the question synopsis, but I dont recall a mother. The MC can't control himself yet, so he has this watch that manages his condition. But when the agents show up to do their demonstration at the school, they turn off all the electronics, which leaves him feeling faint. And when the parasite escapes, they can't call for help (the top HQ personnel also happen to be out/MIA at this time, so obvious set-up). It eats him partially, but he survives and regenerates.

They evacuate the students and teachers from the school and lock it down, but the agents and a few students are left in there with the parasite, who continues to get stronger and smarter the more it eats. Because the MC is an anomoly the parasite has a particular taste for his special blood which powers them up alot more than other humans.

Answer 3

Kind of a longshot, but could you be thinking of Black Bullet?

In the year 2021, mankind is ravaged by the epidemic of Gastrea, a parasitic virus, and is forced to live within the Monolith walls, which are created from Varanium: a metal that is able to subdue Gastrea. Soon, children who were born with the Gastrea virus and obtained superhuman abilities as a result, are discovered and dubbed "Cursed Children". Due to the Gastrea virus' intervention, the Cursed Children could only be female. Civil Securities are formed to specialize fighting against Gastrea, operating with the pair of an Initiator, who are cursed children, and a Promoter, serving to lead the cursed children. Ten years after the epidemic, Rentarō Satomi, a high school student who is also a Promoter in Tendō Civil Security Agency owned by his childhood friend Kisara Tendō, along with his Initiator, Enju Aihara, conducts missions to prevent the destruction of the Tokyo Area and the world.

....

Rentarō is the protagonist, a second year student in Magata High School and also a Promoter in Tendō Civil Security. Rentarō's parents died in the war against Gastrea ten years ago, and was adopted by the Tendō family, but left the family along with Kisara. Rentarō lost his right leg, right arm and left eye in a fight with Gastrea to protect Kisara, and was saved by Doc's "New Human Creation Plan" which replaced his lost limbs with Varanium. Due to his kind and sincere nature Rentaro is one of the few sympathizers of the cursed children. He usually goes to extreme lengths to help them. This trait also leads many cursed children to either take an interest or become infatuated with him. He uses an XD and is a beginner in Tendō style martial arts in the beginning of the story.

Found with a search for manga parasite "inside a wall"

Answer 4

It's called Kiss x Death by Yasuhiro Kano.

From MyAnimeList:

From the perspective of an alien planet with super-advanced technology and tiny (1/60th the size of a human) inhabitants, planet Earth was the perfect location to banish their worst criminals. Five of said criminals were sent to the planet to be exiled, attached to little critters like frogs and rabbits so they can never be fully active. Due to an accident, these five criminals managed to escape and attach themselves to five different girls that were nearby. The one responsible for the banishment of these five criminals now must detach them from the girls by mouth-to-mouth release.