Hi zmajce!
Are you sure it is Japanese?
As I checked using the google translator and obtained a better translation with Chinese as source text ("Jelena is always in my heart"
Yup, it's indeed Chinese, and the first three characters indeed seem to be a name...
It also seems to be a re-translation into Chinese from another language, because it seems to me a Chinese native speaker wouldn't use these characters for "heart": the characters used here literally mean the physical heart, not the metaphorical one i.e. my mind.