Falling asleep on a stranger

An nagikea au (pretty much any nagikea is an au) Nagisa shiota, an 18 year old boy with only a friend name karma akabane at his side. Both Nagisa and karma were orphans and lived at the same orphanage (duh) Nagisa having abusive parents and were both killed by an assassin known as the reaper (the original koro~sensei reaper) and karma's parents were mugged then shot (batman style). Nagisa was 10 when orphaned and karma the same age but only a few months younger then Nagisa. Once 18 and still not adopted the government gave them a house in Tokyo and are willing to pay all bills for 4 years.