Two high school students like each other, but theyre too shy to confess to each other so they write love letters and slip the letters into their locker. The letters aren't signed with their names so both of them try to figure out who's their secret admirer. There are multiple people, on each side, trying to make their move and secure a relationship with Shun and Yui, but of course the two are curious about who's leaving love letters in their lockers.