[4] Endo lost the majority of matches he competed in throughout 2012 and 2013, a common thing for young wrestlers in Japan as a method of earning one's place in the company and gaining experience.

[7] Happy Motel dropped the championships back to Shuten-dōji on July 20 in a three-way match also featuring Team Dream Futures (Keisuke Ishii, Shigehiro Irie and Soma Takao).

[8] Endo competed in the KO-D Openweight Championship Number One Contenders Tournament, defeating partner Takeshita in the semi-finals on August 24,[9] but losing to Keisuke Ishii in the final.

[16] On September 13, Endo and Takeshita unsuccessfully challenged the Golden Storm Riders (Kota Ibushi and Daisuke Sasaki) for the KO-D Tag Team Championship.

[18] After the KO-D Tag Team Championship was vacated due to Kota Ibushi being sidelined with a cervical disc herniation, a tournament was set up to crown new champions, won by Endo and Takeshita after they defeated Shigehiro Irie and Yuji Okabayashi in the final on December 23.

On August 6, Endo, Sasaki and Mad Paulie defeated Shuten-dōji (Kota Umeda, Masahiro Takanashi and Yukio Sakaguchi) in the finals of a tournament to win the KO-D 6-Man Tag Team Championship.

[35] On April 5, 2019, at DDT Is Coming to America, Endo cashed his Right to Challenge Anytime, Anywhere contract against stablemate Daisuke Sasaki to win the KO-D Openweight Champion,[36] before losing the title to his rival Konosuke Takeshita on July 15, at Wrestle Peter Pan.

[40] On June 7, on the second night of Wrestle Peter Pan, Endo successfully cashed in his Saitama Super Arena Sword against Masato Tanaka to win the KO-D Openwight Championship for the second time.

[44] On December 7, 2021, DDT announced that, at the request of Endo and Jun Akiyama, Kenta Kobashi had endorsed the reformation of the Burning stable (originally formed in 1998, in All Japan Pro Wrestling) for its fourth incarnation.