'Kodoushiteru Shinzou'. Replace shinzo with kokoroif you mean heart in emotional sense. (shinzou means physical beating muscle of heart). This has a sense of present, but if you want to use 'beating heart' in sentences with different senses, you can use 'hakudou no shinzou/kokoro'.
White when translated from English to Japanese is shiro for shiro means white
Chocolate is 'chokoreeto' in Japanese.
Dog in Japanese is 'inu'.
Domo.
Koibito.
Sakarerumono
Owari
Hajime mashite?
Yonbanme
何 (nani)
'Shima.'
Ookami.