Zheng Shi Ruojia

I have a good friend named Zheng Shi Ruojia. I used to wonder: Why do we have only two or three words in our name, but she has four words? This is too strange!
I asked Zheng Shiruojia: "What is your mother's surname, what is his father's surname?" She said: "My mother's surname is high, my father's surname is Zheng, is there anything?" I said: "Nothing, I thought the names of the four words are definitely There will be a mother’s last name in it. In fact, there is no relationship.”
It seems that the Japanese names are all four words. Will Zheng Shiruuga be a Chinese-Japanese mixed-race? However, this, I have not asked her.
Once, the teacher had to print the name of each person. In order to be neat, the teacher simply labeled her name as Zheng Shiruo. This matter was discovered by me, and she did not notice it. The teacher is also true. People are obviously "plus" and she gives "decrease". Zheng Shiruo is not as good as Zheng Shiru.
I think that the four words of the name are more fun than the three words, and the strangeness is different.