KO-D無差別級王座
In February 2021 it was announced that Akiyama had let his contract with All Japan expire and would be freelance. Akiyama then won the KO-D Openweight Championship at Kawasaki Strong 2021 from Tetsuya Endo. On February 15, 2021, it was announced that he had signed a one-year contract with DDT Pro-Wrestling.