KO-D Openweight Championship
Gentaro finally returned full-time on January 10, 2010, when he defeated longtime rival Mikami for the DDT Extreme Championship. After a four-month reign, he lost the title to Danshoku Dino on May 5. In October 2010, Gentaro formed a new stable named Granma with Dick Togo and Yasu Urano. After Gentaro and Urano unsuccessfully challenged Antonio Honda and Daisuke Sasaki for the KO-D Tag Team Championship on November 28, Gentaro also faced Honda in a losing effort for the interim KO-D Openweight Championship on December 26. On February 20, 2011, Gentaro and Urano defeated Honda and Sasaki in a rematch to win the KO-D Tag Team Championship, Gentaro's third time winning the title. On March 27, Gentaro entered the annual Anytime and Anywhere battle royal, a match combining elements of a regular battle royal and a ladder match, where he managed to grab the "Right to Challenge Anytime, Anywhere" contract to earn the right to challenge for the KO-D Openweight Championship at a time of his own choosing. After three successful title defenses, Gentaro and Urano lost the KO-D Tag Team Championship to Munenori Sawa and Shigehiro Irie on June 4. On June 19, Gentaro cashed in his "Right to Challenge Anytime, Anywhere" contract, but was defeated in his KO-D Openweight Championship match by the defending champion, Shuji Ishikawa. Granma folded shortly afterwards, following the retirement of Dick Togo on June 30, and Gentaro and Urano failing to recapture the KO-D Tag Team Championship on July 24. Gentaro returned to DDT on June 3, 2012, when Tomomitsu Matsunaga chose him as his tag team partner, after earning the right to challenge for the KO-D Tag Team Championship. In their title match, Gentaro and Matsunaga were defeated by the defending champions, Yasu Urano and Yuji Hino. On July 30, Gentaro returned to referee a four-way tag team match, after which he surprised one of the competitors, Mio Shirai, and pinned her to become the new Ironman Heavymetalweight Champion. However, his reign ended later that same event, when he was pinned by Michael Mamezawa.