After her werewolf lover unexpectedly dies in an accident, a woman must find a way to raise the son and daughter that she had with him. However, their inheritance of their father's traits prove to be a challenge for her.
Upon being sent to live with relatives in the countryside due to an illness, an emotionally distant adolescent girl becomes obsessed with an abandoned mansion and infatuated with a girl who lives there - a girl who may or may not be real.
Kyuta, a boy living in Shibuya, and Kumatetsu, a lonesome beast from Jutengai, an imaginary world. One day, Kyuta forays into the imaginary world and, as he's looking for his way back, meets Kumatetsu who becomes his spirit guide. That encounter leads them to many adventures.
