Ooh... I quite liked that! That was lovely. I am normally no fan of ballads but this one was gentle, with a playful air that many J-pop ballads lack.
I did think the verses were better than the chorus, though, where she started to "shout" (not really, but she was a bit loud) like she tends to do recently. During the verses, though, I think her voice sounded really great. Could be the production or mixing.