The original song was sung by Bobby Chen, and Richie Jen rearranged the song and sang it again. Actually, it's not plagiarism or anything. It's just a new song, just a cover. For example, some songs were originally sung by male or female voices, but singers of the opposite sex just rearranged the songs and changed them to a suitable tune.
Therefore, Richie Jen's style can only be rearranged and sung, which can only be regarded as a cover.