Mikhail is an Angel who is lowkey bad at being one. Heaven's expectations are just a bit too strict for him, which is why he's applied to fight Demons on Earth. Sadly for him, even if he did do his fighting Demon job, Heaven did not provide him with a wage or housing so he's stuck with his neat freak of a roommate Stefan, who would certainly make a better Angel than Mikhail does.
Through shenanigans and bad puns, these two will get together... so long as Mikhail can avoid ending up on the Demons' wing black market.
In which Mikhail gets kidnapped by Lily and Greg, two Demons who seem to specialise in kidnapping Angels to sell their wings to richer Demons.
This is what happens when you do not own a cloaking device.