猫有九命也只有一心而已
[māo yŏu jiŭ mìng yĕ zhĭ yŏu yī xīn ér yĭ]
This idiom-based nickname literally translates to 'A cat has nine lives, but only one heart.' It means even with multiple lives (many chances), one's sincere feelings or loyalty do not change and can remain constant only towards a single object or person.