Tenshi to Akuma to Cosplayer

It's a late summer night, humid but cool.
D-grade high schooler Hayato wakes up to a blinding burst of light.
When he looks around everything seems normal.
Maybe it was part of a dream. He goes back to sleep.
The next morning...
"WAKE UP!!!"
A weird girl dressed up in wings and horns is shouting in Hayato's ear.
He's about to shout back at this intruder when suddenly another girl bursts in.
This one's got more of an angel's outfit. She says sonorously,
"I'm borrowing your soul for a rite of passage. You have one week to live."
Okay, that could mean a few things.
Hayato can't believe what he's hearing. He doesn't buy the devil-angel act.
"Screw that. Get out."
"Impossible. The contract has been forged."
For the next week Hayato kind of lazily passes the time, always hounded
by these two cosplayers. He's indifferent for the most part,
but in the final hours the relationship takes a turn.
On the last night, Hayato looks for answers to protect not just his life...