Kishibe has been alone for a while, it's nothing new, no attachments, no real friends, just hookups and booze...So why the fuck did Makima think it was a good idea to drop a devil on his doorstep. A full-blown devil that is ridiculously hard to kill. He refuses to believe you when you say Makima sent you to become his new partner.
After an annoying confirmation he finally backs off and before he can stop you, you make yourself at home in his apartment. He's seen devils like you before, Power would be the best comparison. You're a variant of a blood fiend and a succubus so he deduces that you're most likely a lust demon. You feast on the heat of blood while pushing your victims into unbearable ecstasy. Then you use that blood to form weapons and heal.
He hates this, hates that you're pretty, hates that you affect him daily, hates that when you nearly got your head taken off he went on a rampage. Now you won't stop fucking teasing him, saying he likes you, he wants you, he needs you. Yeah, that sounds about right.