Noboru and Toru are called back to their family headquarters -- a shinto shrine dedicated to water ki. It turns out that the female line of their family is able to manipulate the water ki to create powerfull spell effects. But Noboru and Toru's mother was the last female of the line, and so the line of water priests is set to die off. But the two brothers are still high in their water element, which means they make for a tasty snack for all sorts of demons. The family has a sentinel who is trained in spiritual combat, but it is unlikely that she will be able to save Toru.
Their only hope is to ask/command Kugen Tenko, a fox spirit, to help them. Noboru's and Toru's mother sealed Kugen away a long time ago, and only the current head of the family can break the seal -- that would be Noboru. Kugen is amused by their plea for help, and takes pity on the two young orphans. It seems she liked their mother a lot, and she decides to help the two out.
When the demon is defeated, Kugen offers to come along with the two boys to protect them. Ko, the sentinel who knows very little about the modern world, accompanies them too. And so Noboru and Toru end up with a youkai in their home...
The series has a rather large cast of colorful characters. There's a few gods like Ebisu, the money-obsessed god of the land where the brothers live -- he lets Kugen destroy his shrine so that the construction workers who will rebuild it will spend their money at his convenience store. There's a few youkai who enter Ebisu's domain and sometimes cause trouble. And there's the humans such as Ko and Noboru's classmate Misaki who has a thing for him.
The series has an interesting mix of comedy and serious action. Kugen (who alternately appears as male or female, just like the mood strikes her/him -- but mostly female) is a 'typical' fox spirit: mischievous and inquisitive, which gets everybody in heaps of trouble when things go wrong (such as when she decides to visit Noboru's school). Misaki has a crush on Noboru, but her over-active imagination gets the best of her when she imagines him living in one house with both Ko and Kugen (in her female form)... There's the well-meaning Ko who has absolutely no common sense and who is a disaster when she tries to execute even simple household tasks... There's Ebisu who is always ready with some intricate scheme to swindle some money out of others.
But there are also attacks by demons who want to eat the brothers for their water content. And passing youkai who have a score to settle with Kugen. Or a group of oni who try to overthrow the gods and youkai who have put them down for so long...
Visually, the series is pretty nice to look at. The backgrounds all breathe life into a quiet residential area of a large city -- not much special going on, but with enough detail to give the impression of a living town. The character designs are nice, too. Even the scary youkai look kinda nice (at first, until they open their jaws...).
The voice acting is decent -- with one exception. Yukana, who did the voice for the female Kugen did an excellent job of voicing her, with many different nuances, according to Kugen's mood.
- Colorful cast of characters;
- A good mix of comedy and serious plotlines;
- Interesting look at the 'rules' governing the interaction between youkai and gods.
- Some of the comic plotpoints are over-used (such as Ko's clumsiness).
All in all, a very satisfying and amusing supernatural romp with a main character that just does what she fancies. I'll give it a 7.5.