>>2456
Not really. But there is a fan game based on this called 夏死.

First I've heard of this. What's the story behind it?

>>2472
It's a rumor that popped up on old Japanese message boards. There were all sorts of outlandish claims about what it was such as that it was a patch you'd apply to Air, that staff from the game were involved ad that it was being sold at Animate. Only thing that has ever surfaced for real is edited CGs with blood on them, and a fangame based on the concept.