With Oshino gone and school out for summer, Araragi heads into the break hoping to spend his time relaxing, working on his classwork with Hanekawa, hanging out with his girlfriend Senjogahara, and maybe even finding a little time to molest Hachikuji as he wanders the streets. But when his sisters get tangled up in investigating a ring of curses circulating their middle school, the boy finds himself once again involved with strange characters and unexplained oddities. With only his vampiric mistress Shinobu for help, will Koyomi Araragi be able to solve the strange mystery uncovered by his "Fire Sisters"?