What does kaname mean in Japanese?

The name kanna isn't actually just a Japanese name, it's also from India.

The Indian name kanna is a masculine name which means 'Krishna', a Hindu deity (the one who is most often depicted playing flutes in shrines and statues and what-not dedicated to him) who is regarded as an avatar of vishnu. And the meaning of Krishna's name is literally translated to mean 'black, dark, dark blue'.

The Japanese version of the name kanna is much simpler, and can be used for both genders based on the way it's spelled. Kan-na is the feminine form and means 'letters' or 'writing', ka-na is the masculine form and means 'powerful'.