I don't know if any of you guys are familiar with late 90s American pop, but before P!nk did rock-pop she actually did R&B-hiphopish music for her first album. Random, but thinking about what songs from the 70s-90s Kuu could do I thought of this song, although I don't particularly like it or anything, I think she would sing it very well, Kumi-fied:
Then I remembered that the message said it was JAPANESE music covers... so yeah, we probably shouldn't expect and English covers, sadly.