User blog comment:DarkJester4114/Ryujin Mifune 6-star evolution Idea(s) (If you got other ideas)/@comment-16216341-20140811115853

Well ALIM did say in an interview that most of there units in JP will be getting 7*

Its safe to say that Mifune and friends will get 6* aswell

Though its gonna take a while for it to come to Global.