It's like a weird version of that "Yuugai Shitei Doukyuusei" manga... But instead of sexy stuff, you have... Well. Death? Or dying...?
Also how about extreme sports. Because I'm sure that's why people do that kind of thing. They enjoy the thrill of being close to situations that could potentially kill them. You don't have to pretend to stab someone or set them on fire.
I'd go for a series of this only if some middle ground was the plot point. Because sheesh... That's a yandere in making.
Still, it was an interesting read, I'll give it that. Maybe it was just me, but the fact that both times were flukes was kind of easy to predict. Still, didn't expect that kind of conclusion.