Pictures with this character has a tag 黒宮雷華 on pixiv, I believe that's her name. I think it can be transcripted as Kuromiya Raihana. If someone else agree with me, than add the tag.

Added Kuromiya_Raika.

• http://dic.pixiv.net/a/黒宮雷華

So, it reads as 'ka'. I see..