Seven Days War

Mamoru Suzuhara is an introverted high school student who spends his free time reading up on modern warfare. He usually spends time chatting with some history fanatics who are sixty-years-old on average on the Internet.

Upon discovering that his crush, Aya Chiyono, is reluctantly moving away with her family next week, he musters enough courage to ask her to run away with him, to which Chiyono agrees. Consequently, Mamoru, Aya, and four of their classmates set out and camp in the abandoned Satomi Coal Factory. Suzuhara who wishes to elope with Chiyono is slightly disappointed, but that nevertheless marks the beginning of a special summer.

After enjoying themselves on their first day there, they come to a surprising conclusion that they may not be alone in the factory.