Ruka's parents may or may not be deaaaad. He wouldn't know seeing as he ran away from home in his early teens because they didn't love or want him! They were superficially caring but truly pretty inattentive/neglectful, seeing as they never did anything to address Ruka's obvious emotional trauma ("random" crying fits when he was younger in response to their hateful thoughts; heavy emotional withdrawal when he got older.) He has mixed feelings about them but mostly resolves not to think about it.