On a wharf on Tokyo Bay is a small art gallery named Gallery Fake. The owner of the gallery, Fujita Reiji (藤田 玲司), was once a curator at the Metropolitan Museum of Art in New York. He was a learned curator with remarkable memory, keen aesthetic sense, great skill in restoration of paintings, and knowledge of many languages, so he was called "the Professor." However, because of trouble in the workplace, Fujita was forced to quit the museum.

Now he is an art dealer who sells paintings, authentic and fake alike, at extraordinary prices. His motto is, "One without aesthetic sense can't help being cheated out of his money. And, by being deceived, one may learn to distinguish the real one from the counterfeit."

However, Fujita is not a villain?not someone who sells fake paintings just as a means to earn money. He truly appreciates art and the artists who spent their lives to create it. Sometimes he takes paintings from a wicked politician who considers art only as a means of exchanging bribes. Sometimes he tries to restore destroyed paintings. He often touches the lives of those he encounters, and people are attracted to him in spite of himself.

In 1996 Gallery Fake received the Shogakukan Manga Award.

Nikumaru, meaning "meatball" in Japanese, is a seventeen-year-old student at Ninja High School, a special school for the training of ninja. He is short and chubby, but he possesses a super technique known as the "kamikaze", where he stirs up a whirlwind with his feet. The series introduces his many adventures and pranks as Nikumaru meets with his rivals both in and out of school.