It's Machida's first day at her new high school, and the first thing she notices is the pair of girls in her class who are identical in appearance. One of the presumed twins, Kamei, immediately latches on to Machida, begging to become best friends. Machida finds this pathetic, but can't seem to shake Kamei off. What she soon finds out, though, is that Kamei wants to take far more from her than just her time and attention.