The action takes place two months after the events of "Ever17 ~the out of Infinity~".

Takeshi's returned to it's normal, peaceful course. In a quiet and measured life burst hot summer, however, is not bringing anything new in it.

However, this daily routine collapsed after a strange incident. It all started with the fact that in a nearby street, was found dead of a woman with signs of violent death. The air at the scene soaked unusual smell of rot ... from the decaying corpse. In the chest - a huge hole, and internal organs turned out. Strange murder suddenly roused harmonious life of the city. This event has attracted the attention of Sara, and she decided to conduct their own investigation. "Why do not we organize a duet !?." This is the phrase Sara identified developments. So, the duo Ninja-Detective got its birth. In the process of searching for them will be new facts of this mysterious case, and then the secret will be revealed. What unites this event from the past and present heroes? ... It was a period of time, slightly changed the course of the boring summer vacation.

Two months after that incident. (Ever17 events)

Takeda regained his peaceful daily life and lived a life without any inconvenience.

The arrival of hot summer.

The start of a summer vacation like no other.

--- However, such a daily life collapsed due to the occurrence of a bizarre incident.

It all started when a woman's unnatural corpse was found in a neighborhood back alley.

A strange rotting odor drifts across the crime scene...a rotting corpse.

There is a large hole in the chest and the organs are gouged out.

A mysterious murder case that suddenly attacked a peaceful town.

The incident fuels Sara's curiosity and makes her decide to investigate independently. "This is the formation of a ninja detective duo

!?" And now, a ninja detective combination has been formed here. New truths and mysteries revealed by following the incident. And meeting and parting. What is the truth behind the incident that connects the past and reality? It was the moment when the boring summer vacation changed a little.