Rubius arrives in Japan following the trail of his missing cat, Wilson. There, he encounters a mysterious figure who convinces him to immerse himself in Japanese culture if he wants to recover his beloved pet. Rubius proves ready for anything, although he'll need more than determination to overcome the challenges that arise.

Rubius's journey continues, leading him to delve into some curious forms of Japanese-style entertainment. He'll develop his culinary skills, become an improvised model, and even drive a car. And all of this will lead him to a fateful discovery...

Rubius discovers the identity and plans of Wilson's kidnapper and decides to confront him by connecting traditional Japanese teachings with the latest in technology. Can he learn anything from the monks retreating in the mountains? And from enormous manned robots that look like they're straight out of an anime?

The time has come for Rubius to face the Bakeneko in the final battle to save his cat. Given the fearsome nature of his rival, he travels across Japan in search of allies and forges the ultimate weapon to defeat him.