Kana-chan from Kanamemo. Her voice is high pitched o.o lol I could've 投稿されました quite a lot of characters but Kana-chan needs 愛 too x3
あなた might recognize this voice if あなた listen closely... Another hint I kinda have to mention is she's the younger one with short, brown hair XD Now it's just plain obvious if you've seen the other show.