 Mission K4 won the OZ Academy Tag Team Championship on March 1, 2015, beating Mayumi Ozaki and Sakura Hirota at "Forgiveness".They held on to the belts until July, when they lost to Ozaki and Mio Shirai at "2Bad", but regained them one month later in a rematch.Primarily splitting her time between OZ and Wave, Kobayashi won the JWP Junior/Princess of Pro Wrestling Championship in August 2015, beating Rina Yamashita.