What are some female Japanese R&B singers?

My family is moving to Japan, where I haven't lived since I was a couple months old. But I don't know any Japanese artists. I am a huge fan of R&B in America like Alicia Keys. I also like Beyonce too. I am trying to find any female solo Japanese musicians who are R&B that use lots of piano. Also ok with singers that use electronic or synthetic sounds. Prefer piano, but those are fine too. Thanks!