Received Kero-chan pet from the Cardcaptor Sakura Event and wanted to use a Pet Name Tag to set his name as Kero-chan to make giving commands easier.
Name: Kero-chan (original) -> Kero-chan
Result: Error message - That name is already in use. Try another.
Second Attempt after temporarily renaming to just Kero:
Name: Kero -> Kero-chan
Result: Get prompted with a name change confirmation. After confirming, Pet Name Tag is not consumed and no error message appears.
The use of the hyphen (-) does not appear to be factor because trying this with another type of pet will yield the same results as attempt two. Toucan (original) -> Toucan-chan -> Toucan