...Seven people die. Cardiac arrest, every single one. And the coincidence would have gone unnoticed if two hadn't been called in at the same time on the same block, one at an internet gaming cafe and the other at an izakaya. Investigation by detectives and journalists alike have so far amounted to only a week's worth of tired news and tabloid speculation, making a story where there can't possibly be one.
Then a mysterious app shows up on the phones of twenty-two seemingly ordinary people. What's in store next not only crosses entire worlds but could determine the very fate of our own.