Some months after the events of Parasite The Movie - Part 1, Japanese police use captive serial killer Uragami (Hirofumi Arai) in their hunt for alien parasites inhabiting human hosts. He alone has the ability to tell regular humans apart from parasites. Meanwhile teenager Shinichi Izumi (Shôta Sometani) and his friendly parasite Migi (voiced by Sadao Abe) hunt and kill evil parasites in an ongoing effort to protect humanity. Unbeknownst to Shinichi and Migi, they are shadowed by former schoolteacher Takeshi Hirokawa (Kazuki Kitamura). He captures their exploits on camera at the behest of fellow high school teacher Ryoko Tamiya (Eri Fukatsu), not knowing she herself is an alien. As the other parasites in human guise place themselves in positions of authority and plot the downfall of the human race, ostensible leader Ryoko finds her attitude to humanity changing now she is the mother of a human baby.
It is hard to gage why Parasyte The Movie: Part 2 had such a frosty critical reception from the western press given the film develops the intriguing themes and ideas established in part one quite admirably. The sequel is somewhat a film of two halves. The first surprisingly sidelines ostensible lead protagonists Shinichi and Migi to foreground the fascinating Ryoko Tamiya. Portrayed with a quite splendid clinical alien precision by Eri Fukatsu, she emerges an intriguing anti-hero who as result of dawning maternal instinct and almost-romance with the luckless Hirokawa teeters between calculating intellect and slow-blossoming compassion. Indeed the relationship between Tamiya and Hirokawa, whose unrequited crush on the alien ice queen leads to misjudgements with tragic consequences, has more impact on the plot than the admittedly sweet romance between Shinichi and his schoolgirl sweetheart Satomi (Ai Hashimoto). Scenes between Tamiya and her infant son tread delicately from creepy to moving as gradually the alien discovers her latent humanity and is alternately bemused, repulsed and fascinated.
For the first sixty minutes or so, Parasyte The Movie: Part 2 functions as a highly cerebral sci-fi thriller. Through the Ryoko Tamiya character the film intelligently translates the philosophical preoccupations and social satire inherent in Hitoshi Iwaaki's manga, making sly observations about Japanese society. It so happens the Japanese tendency towards conformity and reticence about expressing inner feelings provided the perfect backdrop for the parasites to slip in unnoticed. Admittedly Tamiya's plea for tolerance rings a little hollow given she and her fellow parasites continue slaughtering innocents. At times the aliens' pseudo-philosophical argument that humanity are the real parasites skirts close to the self-justifying rants of fundamentalist terrorists. However, in its more thoughtful moments the screenplay implies to unsettling effect the notion of 'humanity' as an ephemeral concept on which we as a species have a frail grasp.
After the supporting characters exit the plot, the film shifts gears becoming a more conventional effort centred on Shinichi's escape from and eventual battle with Goto. The formidable villain is a five-parasite-in-one-host body portrayed by Tadanobu Asano, Japan's chameleonic heartthrob equivalent of Johnny Depp. Thereafter things start to resemble a James Cameron-style, fast-paced SF action movie (at one stage, Cameron was interested in adapting Iwaaki's manga as a Hollywood movie) with body horror sequences part-inspired by Rob Bottin's groundbreaking effects work in The Thing (1982). While less stimulating on an intellectual level, the second half remains compelling, even moving at times, expanding the key relationships and even staging a sex scene that is genuinely emotional rather than merely titillating. Seasoned genre filmmaker Takashi Yamazaki deftly captures the unique schizophrenic tone of the manga with its delicate balance of body horror and quirky comedy.