念你南笙

Here, '念你' means 'thinking about you', and '南笙' can be translated as 'Nan Sheng'. This could either be a proper noun - a name or alias; or symbolically, where '南 (Nan)' can imply warmth and ease like the south wind, while '笙 (Sheng)' is a musical instrument in China that has beautiful sounds, thus indicating someone special and full of memories to the person who uses this nickname