KO-D Openweight Championship
Harashima would reform Disaster-Box with Toru Owashi and on October 26, they won the KO-D Tag Team Championships by defeating Mikami and Tanomusaku Toba. On November 30, Harashima and Owashi successfully defended their titles against Shuji Ishikawa and Sanshiro Takagi. On December 28, Harashima unsuccessfully challenged Takagi for the KO-D Openweight Championship. On January 24, 2009, Harashima and Owashi lost the KO-D Tag Team Championships to Kota Ibushi and Kenny Omega. At Judgement 2009, Harashima won a battle royal making him the number one contender for the KO-D Openweight Championship. On May 4, Harashima defeated Takagi to win his third KO-D Openweight Championship. At Ryōgoku Peter Pan 2009, DDT's first event at Sumo Hall, Harashima lost the KO-D Openweight Championship to Kota Ibushi when Ibushi debuted his new Phoenix-Plex finishing manoeuvre. The following year, on May 30, Harashima won the 2010 King of DDT which he used to challenge Daisuke Sekimoto for the KO-D Openweight Championship. At Ryōgoku Peter Pan 2010, Harashima won his fourth KO-D Openweight Championship. Harashima made two successful defence against Daisuke Sasaki on August 29 and Danshoku Dino on October 24, before losing the title to Hikaru Sato on November 14. In late 2010, Owashi announced his retirement from professional wrestling and that he would be leaving DDT at the end of the year. On December 26, Harashima, Owashi and Yukihiro Abe won the UWA World Trios Championship from Hikaru Sato, Michael Nakazawa and Tomomitsu Matsunaga. The trio would vacate the titles due to Owashi's retirement.