Some mysterious occurrences befall an innocuous student in HOURGLASS OF SUMMER. Swept up by the idyllic summer, he decides to pursue the object of his affections, Kaho, and ask her out on a date. But when he wakes on the day that the date is set for, he realizes that he has somehow missed an entire day, and must return to school. Understandably confused, there is further cause for concern when he gets to school, only to discover that Kaho has been killed in an accident. Spinning into a daze, he must attempt to unravel the mystery of what happened to Kaho, and try to figure out what occurred in the day that somehow just slipped away in his sleep.