Hiroto dreams of building a secret base close to his home. In the storeroom of his house he encounters Tonkachi, a ninja who is also a Nintuber. Tonkachi is aware that something called the Ninja Box exists, and the two end up traveling to the Village of Tatemakuri. There they cross paths with Tatezō, a dog who can talk. Across six online episodes, the story mixes action, comedy and fantasy adventure.