Yattarō is the main protagonist of the series. He is the leader of the Secret Ninja Team, Nyankee".
Yattarou is a typical citizen of Edoropolis. In normal life, he is an excitable, bright, and cheerful fellow.He is often trying to win the heart of his love interest, Omitsu, often referred to as "Omi-chan". Yattaro often comes off as a goof. As such, he can be very clumsy and often makes mistakes. He also suffers from bad luck streaks such as falling off from bridges or buildings, and occasionally botching up a pizza delivery order, usually if something bad happens or if he skips work to visit Omitsu. Despite this, he is pure of heart and is always thinking of others' concerns and does his best to help people.
His relationships with Sukashii and Pururun slighty differ from one another. With Sukashii, Yattaro often gets into arguments and scuffles when one insults the others' habits usually to make each other look bad. Like Yattaro, Sukashii is also trying to earn the affection of Omitsu and this often leads to many of their fights. Despite this, Yattaro and Sukashii likely have a brotherly relationship with one another and can even agree on certain point of views such as Pururun's short-temper and habit of bossing her teammates around at the resturant of which often leads to getting bashed on the head with a frying pan. His relationship with Pururun is an important element in the series. While he gets along well with her sometimes, Yattaro is often afraid of her vicious temper and will usually get beaten or scolded by her when he says or does something foolish. However, as the series progressed, the two seem to have grown closer together and when one is depressed, the other tries to cheer him/her up.
When in battle, Yattarou lives up to the meaning of his name and does whatever it takes to protect the citizens of Edoropolis. He takes fighting crime very seriously and when he expresses his point of view of how the Karakara clan is taking advantage of the city, he speaks in a very seldom voice and strongly detests the misery they are causing. Yattaro is probably the most serious of the Nyankii when it comes to protecting his town. His strong dedication to Edoropolis and the ninja code may be the reason why he may be the leader. Yattaro has a strong rivalry with Karakara leader Karamaru. Both commanders are highly skilled swordsmans and have even challenged each other during battle while their followers take one another on. This rivalry has eventually led Karamaru to have a one-on-one showdown at sunset in a suit of armor (Episode 37).
Yattaro wields the sword known as the "MasaMasa" and often unleashes his move "Neko Me Slash" (Cat's Eye Slash).