Has there ever been something so valuable to you that its loss would leave you completely bereft? Otokawa Natsuru can answer that with certainty - for her, that possession is a keychain. Prompted by the advice of Kazama Miori, a classmate renowned for her psychic abilities, Natsuru brings her beloved keychain on a date with childhood friend Yanagi Eitaro with the hopes of strengthening their relationship. Tragically, Natsuru misplaces the keychain during the course of their outing.