Kiseijuu

Alien parasites arrive without warning, descending from the sky and invading human hosts to survive. These creatures can take on various deadly forms, such as beings with large teeth, winged figures, or hands transformed into blades. Many hide their true nature by adopting human appearances, keeping their secret unknown to most. A high school student named Shin is fighting to maintain control of his own body against one such parasite. He faces the challenge of alerting others to the growing threat without revealing the presence of these hidden invaders.