This is what I'm getting at, though, it's the same with the promortalists and I'm certain other morbid groups.
One person commits suicide who is the friend of people obsessed with death. The others are even further depressed by this ultimately leading to their own suicides. They're like lemmings. But, ultimately there's a megaphone their all listening to that endorses and encourages a morose outlook and hints at death being a release.
Not to say specifically this game in this case, Aya might have found something else to validate his suicidal ideations.