According to the inquiry, in the cartoon "Cutting Teeth", Yong Ichiro is the grandfather of Yong Jiro. He once defeated an entire fleet by himself, and was known as "the strongest man in the world" and the strongest human being officially set. Although Yujiro is known as "the strongest creature on the surface of the earth".

The strength is still not as good as his grandfather Yong Ichiro. When he was young, Yong Ichiro often taught him a lesson and made him afraid of Yong Ichiro, so he was afraid of Yong Ichiro and wanted to beat him most.