Darumiru is the god who Ariyuki unkowingly called. She came crashing down to earth in the form of a meteorite causing the destruction of the Asata household, which, of course, was repaired by her later on. Though her powers are very useful, she needs a vessel to use them, and by using her powers, her vessel, Ariyuki, will suffer "recoil", which is basically diarrhea. She tends to get clingy to Ariyuki at times and more so when Kei gets or tries to get close to him. She later seems to develop feelings for Ariyuki.
The name "Kogoria Flonmell" was only made up by Kameji when he filled-out Darumiru's identification papers so that she can enter their, Ariyuki and Kameji's, class.