Best House
The homeless man is way too carefree. He's going to die, or, he has depression, or he's a psycho who'll kill Yuuma, or he'll end up killing Yuuma and himself. In the cover, what's that gas tank behind the homeless man? The woman who collapsed behind Yuuma must be his mom, who died. -spoiler- Edit: I found the raws, but they had to be paid for. But there's a "free sample," a little glimpse of every chapter. So, in the last chapter, Kiri collapsed in front of Yuuma and then a weird glowing bubble appeared. I'm not sure if the bubble was Kiri or a different person, but the bubble says that Kiri came to the rooftop to die, and then Kiri or the bubble says something like "My heart is empty/dark" and then the panel shows Kiri's half-naked body with a huge dark hole in his chest and then the free sample cuts there, so I'm not sure what happened, but I'm assuming Kiri was already dead from the start.
December Rain