For clarity since the translations don’t specify, this scene was a test. The ML read off a book title that is written in the language that was used in Korea hundreds of years ago. Then the ML used that same language to ask the MC about the measurement of their height difference. The MC shouldn’t know these words or how to read them if he were just a regular student and the fact that he does understand the language and also couldn’t say how old a high school student would be completely gave away that he is much older than he’s pretending to be.
For clarity since the translations don’t specify, this scene was a test. The ML read off a book title that is written in the language that was used in Korea hundreds of years ago. Then the ML used that same language to ask the MC about the measurement of their height difference. The MC shouldn’t know these words or how to read them if he were just a regular student and the fact that he does understand the language and also couldn’t say how old a high school student would be completely gave away that he is much older than he’s pretending to be.