The Country of Tanabata

A small group of people, descended from a particular bloodline, have the ability to negate a sphere of reality and neatly remove it from existence. Continuous use of this power alters the user's appearance until they come to resemble a none-too-pretty alien.

But what does this have to do with an out-of-the-way town in Japan, a group of university students from Tokyo, and a series of mysterious disappearances and deaths?