Kyotaro Kakei is a shy student at a prestigious academy known for its massive library. The sole member of the school's library club, Kyotaro's always been better with books than girls – until a text message from the mysterious "Shepherd" hints that his fate will soon be changing. Life gets wild in a hurry after a vision allows Kyotaro to rescue Tsugumi, a beautiful girl who also received a text message from the "Shepherd." Soon, Tsugumi announces her intentions to join the Library Club and, with Kyotaro's help, make school life much more interesting! It doesn't take long for a host of other pretty girls to follow Tsugumi's lead and join the club in the hopes of spicing up their boring academy lives. But just who is this "Shepherd," what does he or she have to do with the Library Club's sudden popularity, and how in the world will Kyotaro survive being surrounded by all these girls!?