Eien ni Korosare Tsuzukeru Natsu

High school girl Shinko and her childhood friend Hiroki wander into a day of recurring horror, but is it real or not? After school, they were relaxing in the park as usual, when a mysterious man appeared on the chime of five o'clock and attacked them, murdering them both. When they woke up, they have somehow returned to the morning of that same day. The two had to experience that evening of terror again and again. To escape from the time-loop of killing, the two try to fight back in any way they can... (Source: piccomics, translated)