Is Japanese Shinji Ishibe a historical allusion figure? What kind of person is he?

In Japanese, "Shinji Ishibe" is not a historical allusion figure, but is related to a place name.

There used to be a big copper mine called Shibe Jinshan in Shibe Town, Shiga Prefecture, Japan. Now, in the west of Shibei Railway Station, you can still see the remains of the past mines. From the hardness of copper ore, strong and stubborn people are called "stone ginger"

Your translation of Shinji Ishibe as a "stiff and inflexible person" is completely antonym. In a sense, this translation is correct, but in Japanese and Japanese culture, "Paul of Ishibe" is obviously positive, with a strong and lasting meaning in it. Besides, words like "stubborn" have positive meanings in Japanese. For example, many traditional restaurants will flaunt their "stubbornness".