One of the protagonist of 19 Days - One Day is called Zhan Zheng Xi. Or Zhan Xixi. I'm not sure, because he's been called all three:
Zhan Zhengxi
Zhan Zheng Xi
Zhan Xixi
The first two I can attribute to translation from Chinese to English. What about the third one, Zhan Xixi? Does he have four names, as in "Zhan Zheng Xi Xixi", or is it something else?
All images taken from here.
It's Zhan Zheng Xi.
...and not Zhan Zheng Xi Xixi.
They are such that the first word in the name is the surname, which is different from "English" names where the surname comes after the name.
Essentially, the first word in this character's name is: 'Zhan'. This would be the surname, also known as 姓 (xìng).
The subsequent two words are the character's personal name, which their parents choose for them. This is also known as 名 (míng). This personal name is almost always disyllabic, with a small exception being monosyllabic. In this case it is disyllabic -- 'Zheng Xi'.
To give an example: Take Harry Potter and Zhan Zheng Xi. The former's surname is Potter, and the latter's surname is Zhan. The former's personal name is Harry, and the latter's personal name is Zheng Xi.
'Zhan Xi Xi' isn't wrong as well, it would classify as a "nickname" given to the character by his friends. Take Ronald Weasley for example. He's not always called Ronald. Instead, he's called 'Ron'. Same thing here, Zheng Xi can be abbreviated into Xi Xi.
The following Latinized transcriptions - Zhan Zhengxi, Zhan Zheng Xi, and Zhan Xixi - are all Latin-based, specifically Pinyin-based, transcriptions of the original Chinese characters.
The Zhan surname may refer to: 展, 湛, 詹, 占, or 战/戰. They are all converted into Zhan in Pinyin. Without reading the original Chinese, it is impossible to know which logogram is the character's real surname. Same goes for the given name. Chinese is a tonal language, and the tone can help with logogram identification. But even then, it is a wild guess . . . unless someone reads the original Chinese.
The character's real name may be 展正喜. 正 is a fitting name for a boy. It is used in Kim Jong-un's Hanja name. 喜 makes sense for a boy; a boy gives pleasure to his family. In Pinyin transliteration, the name may be written as ZHAN ZHENG XI, treating each character as a separate word. The name may also be transliterated as ZHAN ZHENGXI, treating the family name as one word and the whole given name as another word, similar to English format. In English name order, 展正喜 may be written as ZHENGXI ZHAN, because ZHENGXI is the given name, and ZHAN is the family name. However, ZHENGXI ZHAN may be too obnoxious, because no one writes the name in all capital letters. So, Zhengxi Zhan would be preferred. If the guy chooses an English name, such as Brian, he would be known as Brian Zhan.
In the first picture, the name is written as Zhan Zhengxi, because that is currently the set Western preference for writing Chinese names. In the second picture, note the exclamation points. That should tell you that the character utters each syllable separately and emphatically. That's why it is separated. In the third picture, Zhan Xixi may be a "little name"（小名）or a nickname（外号）. The "little name" is a special kind of nickname given at birth, making it different from a regular nickname.
