Those are bizzare and surreal series that strongly resemble "Propeller Heaven".

However, the problem here is that story leaves less impact than propeller heaven.

The story revolves around a group of school girls that have to fight aliens by wearing helmets (That are aliens themselves). It is not really possible to explain more without spoiling it.

The series have old school character graphics with round and slightly cartoonish faces, but this is contrasted by detailed depiction of aliens, surroundings and the like.

It is very difficult to make sense out of the story, until at some point it goes and explains half of it in an informational dump during inroduction.

Characters have varying degree of although the lead(?) character behaves as a girl would, the rest are less coherent and more confusing.

In the end I think this manga is worth checking out largely due to surrealism and quality artwork. However, I feel like "propeller heaven" left bigger impact on me when I read it.