Matt Alt: Others are connected to odd physical sensations, too: the Nobiagari, who we cover in Yokai Attack!, is a yokai that is pretty much the personification of a situation when you feel like someone is following you, but there's no one there.

Hiroko Yoda: Or Nurikabe! The living wall, he's why you sometimes feel like you're stuck and not making any progress through dense forests or wherever you're trying to get out of.

And there's another one called Buru-Buru, or "the Shiverer," which is a yokai that makes you involuntarily shiver.

Q: In American traditions, Halloween / October is the time for ghosts and spirits -- but in Japan, summer seems to be the season for ghost stories / haunted houses. Why is that?

Hiroko Yoda: Summer is definitely "horror season" in Japan. In the era before air conditioning, they say that people used to get together and tell ghost stories and shiver to cool down. That's a very traditional form of entertainment in Japan.

Also, we have a summer tradition called Obon, which is a custom in which the souls of loved ones who have passed away come back to visit. The "lid of the underworld" is off, so they say. So the distance between the world of the living and the supernatural world is a lot closer in summer, traditionally speaking.

YOKAI, YESTERDAY AND TODAY

Q: Some of the legends around yokai include stories of people really seeing / experiencing yokai phenomena. Does this still happen today?

Matt Alt: I think in times of old, the line between "natural" and "supernatural" was a lot grayer than it is today. I am sure some people definitely believed in yokai, but you can't say that EVERYONE did, even back then.

Hiroko Yoda: I don't think many people, if any, seriously believe in kappa and tengu today. But that said, they are wonderful stand-ins for respecting the natural world around us. Yokai are characters, not from anime or manga but rather in the drama of the natural world. This is why they have sort of taken on a mascot-like role in modern Japan.

Like Matt said, though, it's a big country and you can't say unequivocally what anyone believes. There's a saying in Japanese called "hanshin-hangi" which means neither believing nor disbelieving. Think Fox Mulder in the X-Files: "I want to believe!" (laughs)

Q: A lot of yokai seem to be based in Japan of the past -- but are there modern-day yokai?

Hiroko Yoda: There are a few modern yokai. Probably the most well known is the Kuchisake-Onna, "the slash-mouthed woman." There was a huge rash of "sightings" among elementary school kids when I was growing up, and I definitely remember talking about her with my friends. She looks like a normal woman, but wears a surgical mask and basically stalks kids on their way home from school.

Another is called Toire no Hanako-san, "Hanako in the Bathroom," and is a lot like the spirit that inhabits the school bathroom in the Harry Potter movies.

Q: In Hawaii (a place with a large Japanese-American population), there are legends about a faceless woman who'd be found sobbing in the restroom of the local drive-inn theater, and inu-gami spirits who possess people. Do yokai exist wherever Japanese people live in other parts of the world?

Hiroko Yoda: I really like the concept of Japanese yokai taking a "vacation" in other parts of the world, and that's exactly what I think when I hear about the "mujina" -- "the faceless ones" -- in Hawaii. But sure, if yokai exist in the hearts and minds of Japanese, it is only natural that they might be seen wherever Japanese people are.

YOKAI LIVE... IN MANGA AND ANIME THAT IS

Q: There are lots of yokai in manga, film and anime, but probably the most famous is GeGeGe no Kitaro by Shigeru Mizuki. So in your opinion, what makes GeGeGe no Kitaro so special to Japanese readers?

Matt Alt: Mizuki-sensei's genius was in taking dusty old folklore and breathing all new life into it for kids (and adults) to enjoy. He basically singlehandedly kicked off the fad for things yokai in the 1960s in Japan and it hasn't really let up since.

We've never had the pleasure of meeting him, but both Hiroko and I are big fans of his work.

Q: Tell me a little bit about the book. What inspired you two to work on this project? How long did it take to pull all this material together?

Hiroko Yoda: We'd always wanted to do a book like this, almost from the very first time we talked about yokai together. But it took quite a while for that dream to come together as an actual concept, a pitch to a publisher.

We did another book together first, called Hello, Please! which is a pocket-sized field guide to Japanese kawaii (cute) culture and cute mascot characters, and that gave us the experience and confidence we needed to really pull Yokai Attack! together.

Q: The illustrations in Yokai Attack! are by Tatsuya Morino, who is a former assistant to Shigeru Mizuki. How did you get him to work with you on this project?

Matt Alt: Morino-san was part of our circle of friends even before we came up with the concept of the book. He's actually a huge toy collector, and so when I gave him a copy of the first book I co-authored, Super #1 Robot, he was one of the only people I met who actually remembered and could name all of the robot toys we'd put inside! So our friendship started because of robots.

There's actually a lot of crossover between, say, Gundam fans of a certain age in Japan and GeGeGe no Kitaro fans, because they're both of the same era.

Anyway, when we got the idea to make a yokai book, Morino-san was the natural choice. We didn't even consider anyone else. And Hiroko and I are so happy with the way the art turned out. He really has yokai in the blood... Maybe literally?