KO-D無差別級王座
In order to combat Kudo's new stable with Masa Takanashi and Yukio Sakaguchi, known as Shuten-dōji, Harashima and Urano formed Smile Squash with Akito. On May 25, Harashima won back the KO-D Openweight Championship from Kudo. At Ryōgoku Peter Pan 2014, Harashima made his third successful title defence in a three way against Kenny Omega and Isami Kodaka. Continuing into 2015, Harashima had made seven successful title defences before he lost the KO-D Openweight Championship to Kota Ibushi on February 15. He regained the title from Ibushi on April 29 for his seventh championship reign, surpassing Sanshiro Takagi's record of six, only to lose the title to Kudo on May 31. At Ryōgoku Peter Pan 2016, Harashima faced NJPW's top star Hiroshi Tanahashi in a losing effort. On September 8, Smile Squash unsuccessfully challenged Team Dream Futures for the KO-D Six Man Tag Team Championship. On October 25, Harashima unsuccessfully challenged Yukio Sakaguchi for the KO-D Openweight Championship. On November 17, Harashima was able to gain a measure of revenge over Tanahashi by defeating him in a tag team match, pinning Yohei Komatsu. On December 31, Harashima teamed with Yuko Miyamoto to take part in the 3 Organization Shuffle Tag Tournament and reached the finals before losing to Daisuke Sekimoto and Konosuke Takeshita. On February 28, 2016, Harashima became the number one contender for the KO-D Openweight Championship when he defeated Shigehiro Irie. At , Harashima defeated Isami Kodaka for his eighth KO-D Openweight Championship reign. After making his first successful defence against Kazusada Higuchi, Harashima lost his KO-D Openweight Championship when Daisuke Sasaki cashed in his "Right to Challenge Anytime, Anywhere" contract. In the summer, Yuko Miyamoto joined Smile Squash, teaming with Harashima as Smile Yankees. At Ryōgoku Peter Pan 2016, Smile Yankees defeated Kai and Ken Ohka to win the KO-D Tag Team Championships. On September 25, Smile Yankees defeated Damnation's Daisuke Sasaki and Tetsuya Endo to make their first successful title defense of the KO-D Tag Team Championships. On October 9, Miyamoto and Harashima lost the KO-D Tag Team Championship in the second title defense to Sasaki and Endo in a rematch. After defeating Endo on October 23, Harashima would defeat Damnation's Shuji Ishikawa for his ninth KO-D Openweight Championship. On January 29, 2017, Harashima successfully defended his title against the Damnation leader, Daisuke Sasaki. On February 12, Soma Takao joined Smile Squash whilst Akito would leave on March 25. At , Harashima lost the title to Konosuke Takeshita.