你是我的春夏亦是我的秋冬
[nĭ shì wŏ de chūn xià yì shì wŏ de qiū dōng]
This means 'you are my spring and summer as well as autumn and winter', symbolizing that the person holds irreplaceable meaning in one's life—irrespective of time, season, mood or circumstance; always present through every phase and change within them.