This is a review of the whole series (three volumes).

The main concept of this story, which is unveiled slowly so it’s somewhat of a spoiler, resonates with the notion that likely most depressed people have had at some point: that they are inhabited by an alien presence that feeds upon their anguish. But the story goes further: what if that alien presence has actually caused a symbiotic relationship? Although the parasite leads the host to isolate itself and develop troubling compulsions and/or fears (like germophobia or scopophobia), the alien presence also acts as a dam of sorts, consuming the excess anguish that would otherwise overwhelm the host and lead him or her to suicide. Maybe worse: what if love itself is a lie fabricated by these alien presences to manipulate human beings into doing their bidding?

Our protagonist is a germophobic twenty-seven-year-old programmer who develops a virus that will shut off telephone and SMS services during a few days of the Christmas holidays. He rationalizes the fact that he feels lonely during that period, so he would prefer if other people weren’t able to contact their family members or their romantic partners. Some mysterious older guy finds out about his intentions somehow (this ends up having surprisingly little to do with the rest of the plot), so he blackmails him into being the babysitter of a troubled seventeen-year-old girl who refuses to attend her high school classes.

This high schooler suffers from scopophobia as well as misanthropic tendencies that have led her to quit society. Initially it seems that this girl’s “handlers” are partnering her with somewhat like-minded individuals in the hopes that these third parties will end up convincing the girl to go back to school and behave like a proper human. However, the truth is more complicated, hence the parasite thing in the title.

The story ended up being far deeper and philosophical than I expected. However, I was tempted to rate it lower because it never quite nails the execution. Some of the character designs are a bit too samey; combined with some extended flashbacks awkwardly introduced, at times I wasn’t sure if some characters were the same but with different haircuts. I’ve lived plenty of years already but I doubt I’ve gotten that senile, so I suppose that my confusion was due to this manga’s shortcomings. Also, I thought the protagonist was a bit weak. For most of the story there was little more to this guy than his germophobia and his tendency to isolate himself.

I particularly enjoyed the ending. It was bold but subdued in a haunting way.

In any case, good story. I wasn’t too surprised to find out that this author also wrote the manga ‘I sold my life for ten thousand yen per year’, which is great if you are into psychological pain.