(Manga) Girl in (high?) school fighting alien/monsters that are disguised as students, but erupt into large puffy monsters

Question

Probably read 10 years ago. But don't know how long before that it was originally released. I read it on one of those manga translating sites in English, but was probably originally in Japanese when released.

Pretty sure it was a long story (~200 pages) but was probably published as typical series of 30-40 page Mangas originally? Pretty sure it was adult oriented, but did seem more story focused that your typical hentai.

The Story was of a girl in school, who discovers that some of her classmates are aliens or monsters who disguise themselves as humans. When they are discovered, or threatened, or want to attack, they erupt from their human disguise much like the "Faceless" aliens in the XCom video games. Although more fluffy or plush. More like a teddy bear 2x larger than their student disguise.

If I recall correctly a group of the aliens are running around cornering individuals and molesting/absorbing them into themselves. (feeding? or changing them into more aliens? I can't recall)

The heroine witnesses an attack, (a group of boys attacking/molesting a girl) and when discovered, they chase and capture her also. BUT for some reason touching her in their alien form kills them. They start quickly melting away as if her touch is acid to them. (I think ending as a puddle of goo on the floor or all over the heroine)

I remember several instances of different groups of the aliens trying to capture her and dying when they touch/molest/absorb her.

The aliens may also have the ability of hypnosis in that people other than the heroine would not "see" the attacks happening. I seem to recall a scene where a few of the aliens grab the heroine in a courtyard of the school, and either because the aliens die, or they are to far away from the other students, the other students can finally see what is happening.

Anyone recognize this series?

Answer 1

Alice in the Alien World seems like a good fit.

From Baka-Updates:

Nogawa Izumi is a good student, and a class representative, but she has an increasingly high libido. It's gotten to the point that she'll claim to feel bad during class, so she can run to the nurse's office and masturbate. When she learns that the Earth is being invaded by aliens that look like people dressed up as animals, it turns out her high sex drive may be able to help protect the Earth. The first time Izumi is attacked by the aliens, she is rescued by Usayama, a bunny alien whose race was their previous victim. Usayama gives her a swimsuit that will allow her to fight the aliens, but which also sends her constant arousal through the roof. The scientific organization that Usayama is affiliated with think that Izumi, with her high erotic level, may be the person they've been looking for to fight the aliens. Will Izumi be able to save the Earth?

It's certainly an adult-oriented, black & white manga, with nudity and sexually explicit scenes.

The plot involves an alien invasion of Earth by aliens who can disguise themselves in human skinsuits, but also burst out of those disguises into larger forms, resembling giant stuffed animals. The aliens are repeatedly shown sexually assaulting human high school girls.

The heroine is a high school student herself, who's given a special bikini by a friendly alien, which enables her to seemingly melt the malevolent aliens with physical contact.