What is the usage with these names? The TV movies 流星花園 made in 2001 and 2008 have characters named 道明寺,  花澤類, and  藤堂靜, who are usually called 寺, 類, and 靜.  I think those are just the second syllables of the two-syllable given names.  Am I wrong about that?

I believe I know what is happening.  These are families that continue using part of names. So 道明寺 has an older sister 道明莊 and mother 道明楓.  So I guess people call 道明寺 just 寺 because that is the unique part of his name in the family.  But, is that right?

I guess it is sort of like generation names (https://en.wikipedia.org/wiki/Generation_name).  But in these families the names are not just for one generation, and girls and boys both get them.  Am I wrong?  Or is that what they are doing?
道明寺, 花澤類, and 藤堂靜


All Japanese names:

道明 (Michiaki) is family name, 寺(ji/ Tera) is first name

花澤 (Hanazawa) is family name, 類(Rui) is first name 

類 sound strange in Chinese name, but it might have been Japanese 平假名 "るい" translated to 漢字. When a Japanese name contains 平假名 instead of Kanji, The Chinese translator would choose a Kanji with that pronunciation, and they usually have more than one choice. 
Take るい (Rui) for example, it can be one of the following Kanji: 塁 涙 累 類 泪 壘 羸 縲 瘰 誄 

累 and 泪 are female names; 壘 and 類 can be male names

藤堂(Todo) is family name, 靜 (Shizuka) is first name


  I think those are just the second syllables of the two-syllable given names.


If a Chinese name is made up of a one character last name and a two characters first name, you can use the entire first name or just the last character to address that person. 

Example:

You can address "劉志雄" as "志雄" 

It is not wrong to address "劉志雄" as "雄", but it is very informal. (use only to people who are very close to you)

In most cases, when addressing someone with his first name , we would add name prefix 阿，(as in 阿雄)