Technology has made a huge breakthrough over the past few years with the invention of nano-machines that affect the mind of the target after getting into his blood. Police, security and insurance companies in each country collaborated to deal with the situation and established a secret ASTCIS (Anti Silent Technological Crime Invisible Shields) organization.

Hero has just uncovered plot of "Blue bloomers" female band to infect the minds of high school girls by selling them bloomers from a special fibers. His next task is to discover the secret Spiral Institute that is located somewhere in a hotel of an isolated island. So starts his exploration.

[From vndbreview]