Seira Saotome, the silver-haired beauty sitting beside him, is known as the class's very own "saint." Kind and considerate toward everyone, she seems to have no flaws—but appearances can be deceiving.

It all begins when he picks up a piece of black fabric that has fallen from her pocket. Soon, mysterious messages start arriving every day, and he discovers that the class's beloved saint has a surprising secret.

A skirt slowly lifted as if testing his reaction. Sweet, irresistible temptations without warning. What awaits him is a secret and seductive romance with a not-so-innocent "saint."