Can't find KKBOX in Google Play
KKBOX is currently available in Taiwan, Hong Kong (including Macau), Malaysia, Singapore and Japan.
Ensure the country/region of your Google account is set to the country your KKBOX account was registered under by referring to Google Help.
You should find KKBOX under Google Play after that.
Devices (regardless of brand) purchased in Mainland China may be equipped with Google Play that does not support In-App Purchase, therefore you will not find, or is restricted from installing KKBOX.