The drama tells the story of a group of seven university students who travel to a deserted island where a strange decagonal mansion stands. It was the scene of a grisly mass murder six months earlier, and events soon turn ominous.

Asuka Yukihira (Alice Hirose) is 28 and works at the reception desk for a music school. She hears that her high school will soon be abolished and decides to attend a school reunion held at her high school. There, Asuka Yukihira meets Haruto Mizuno. Asuka Yukihira liked Haruto Mizuno when they were high school students, but she never conveyed her feelings to him. Asuka Yukihira and Haruto Mizuno talk during the school reunion and they learn that they both had feelings for each other and they still feel the same way. Asuka Yukihira is ecstatic, but, the next day, an unexpected tragedy strikes Haruto Mizuno. That leaves him in an unconscious state.

A tumultuous "pure love" story following a young man, orphaned in Japan and raised by a powerful South Korean conglomerate, as he navigates a fateful reunion and unforeseen challenges.