百变家妹 = baibian jiamei
It's the pinyin for the CN title. It means something roughly along the lines of "Hundred Forms Younger Sister", but given the context of the artist being JP, the title should probably be "My Imouto's Numerous Forms".
@Leveler Let me know if you're fine with the changes.
@raltzero thankz for chanhjng. i was thinking about my sister's several forms as the title, just didn't know how to change the name. eee thnkz for helping :3