When an unseasonably hot summer hits Omiko City, Matsuri, Suzu, Reo, and Soga are tasked with finding the cause, thought to be a malicious ayakashi. But the heat warps the mind in weird ways, and Suzu finds herself drawn to Matsuri even more feverishly than before! Meanwhile, Matsuris flustered over both Suzu and Reos attentions. And what will Soga do when the heat forces everyone to don bathing suits?