[6][7][8] Kobayashi also debuted for OZ Academy in late 2014 and immediately formed an alliance with Kagetsu as "Mission K4", with Sonoko Kato and Akino joining their ranks shortly after.

[11] Primarily splitting her time between OZ and Wave, Kobayashi won the JWP Junior/Princess of Pro Wrestling Championship in August 2015, beating Rina Yamashita.

[15] In January 2017, she partnered up with Sareee to challenge for the World Woman Pro Wrestling Diana Tag Team Championship, where they lost to Crysis (Chikayo Nagashima and Megumi Yabashita).

[16] In June 2017, she revived Mission K4, this time with Akino as her partner, and the two won the OZ Academy Tag Team Championship, beating Hikaru Shida and Syuri at Voyager.

[28][29] After a gruelling 50 minute long match where she eliminated Sonoko Kato and Mayumi Ozaki, Kobayashi was finally defeated by Aja Kong and narrowly missed the chance to become #1 contender.

[30][31] She was scheduled to return to Mexico in September, but announced via Twitter that she had suffered a dislocation and internal ligament peeling in her knee, which would require 3 months away from the ring.

After trading tag team wins and losses for almost 5 months, the two faced off in a 2/3 falls Luchas de Apuestas match at CMLL's Juicio Final pay-per-view on May 31, where Kobayashi was defeated and as a result had her head shaved bald and after which returned to Japan.