Meaning explanation: It's quite popular recently. Used to address girls older than you 18~25. In fact, people younger than you can do it. It is a lovely and kind feeling to call it that.

Source: The appellation of young girls originated from the styles of "Meng Xi", "Little Fresh" and "Second Yuan" on the Internet.

Usage scenario: When you meet a young girl, you can call her Little Sister.

Example: There are many little sisters in the group. These are not stingy men.