Kosaki

Information
Kosaki is a ring Succubus summoned by Keima.

Personality
Even though it doesn't have a body one can imagine its lust for sexual activities.

Summoning
She was summoned by accident. Keima wanted a full-fledged Succubus, which could protect him during his sleep, because Michiru could go inside Keima's room while Niku was there.