My billionaire roommate is the Demon King

Broke painter Emma scores when her gorgeous new roommate pays a year's rent upfront—only rule: never ask his past or open his door. But strange events unmask him as a 900-year-old Demon King posing as a billionaire CEO. An accident binds their souls in an unbreakable pact. Forced into a fake relationship, staged love turns real—just as Emma learns her own origins outshine the demon under her roof.