Here's why:
* Last names can be common across multiple countries and cultures.
* "Saeyang" could be a unique family name with no clear origin.
* There are many languages and variations in spelling, making it difficult to trace origins.
To figure out the possible nationality, you would need more information, such as:
* The person's full name (to see if the surname is part of a specific cultural naming convention)
* Their place of birth or residence
* Any information about their family history or ancestry.
Please provide more context if you want help narrowing down the possibilities.