Keiki Kiryu (voiced by Hiro Shimono) is an ordinary second-year high school boy. Although he also dreams of a sweet love on the high school campus, such love seems to be out of his reach. One day, Keiki finally received a long-awaited love letter, but what he didn't expect was that a pair of white underwear fell out of the envelope. Could it be that the girl who sent this love letter is a pervert? What's worse is that this love letter is not signed, which means that all the girls active around Keiki may be the author of this love letter. Who is the author of the love letter? Tokihara Sayuki (voiced by Taketatsu Ayana) who seems to be high and mighty but is actually a masochist, Koga Yuika (voiced by Hidaka Rina) who looks cute and well-behaved but has a super bad personality, and Nanjo Mao (voiced by Nomizu Iori) who is called a cartoonist but only draws BL comics.