They are among us.
David Vincent had his invaders, Izumi Shin’ichi has his parasites (the “Kiseijû” of the title). Both know what the world isn’t aware of — “they” are among us. Coming from space, hidden behind the faces of people like you and me, but different. Monstruous.
Yet, working within a compiration which objectives and resources were a mystery, David Vincent’s “invaders” had the good taste of dying without putting too much of a fight and disappearing without a trace in an all-consuming red halo.
The motivations of these parasites are far more primal and obvious: feeding (off human flesh, most of the time), and sometimes defending themselves. Nearly invincible, able to shapeshift at will, they become pitiless killing machines, leaving a trail of blood and corpses.

Like David Vincent, Izum Shin’ichi knows they are here. But here, no closed, deserted diner, no man too long without sleep to continue his journey — it’s in his own flesh that Shin’ichi finds out the truth, as one of the parasites has taken residence in his right arm. From forced coexistence to collaboration, those two-heroes-in-one will then try and bring an end to the actions of the visitors of the neighbourhood.
They then start on a bloody quest in which, as in The Invasion of the Body Snatchers, monsters can hide behind the faces of relatives that you meet every day. With its relative short span (10 volumes “only”), the series avoid the cheap overkill of a succession of parasites with increasing power, and renews itself enough to maintain tension and novelty in the narration. But it’s more at the graphical level that this story succeeds, transcending the art that can be too rigid at times.

Previously in Mikan (“Unfinished”, one of the short stories featured in the collection Hone no Oto), Iwaaki Hitoshi was already dealing with the subject of the relation to the body in a story about sculpture and model. In Parasyte again, the body ends up at the center of the story, with the author’s line molding the flesh, borrowing from the animal reign all that is cutting, piercing, biting, scratching, to create his nightmarish creatures. Not completely inhuman but truly monstruous, they are reminiscent of Hieronymous Bosch’s visions of Hell.

Published over ten years ago, there is no denying that Kiseijû is showing its age, particularly in the light of the dark elegance of more recent series like MPD-Psycho. Yet, remain the pacing of the narration and a relative naiveté (especially in the treatment of the central duo of Shin’ichi and his parasite), but more importantly a narrative quality that places Iwaaki Hitoshi’s magus opus far above the forgettable debauchery of action that can be seen in the more current ARMS and Gantz among others.