Continuity mistake: During the final battle between Kenjiro and Collins, Collins starts out wearing a black kimono with white trim, similar to the one Kenjiro is wearing. However, several times during the fight, he is seen wearing the simple blue kimono (without trim) he has used in his earlier fights. His outfit keeps changing back and forth during the entire fight, sometimes black and white, sometimes blue. The absence/presence of white trim makes this very easy to see.
Continuity mistake: While Kenjiro and Collins are talking under the arena, a fight goes on between the blond Australian and a swordsman dressed as Conan, which the Australian wins, killing Conan. Later, while Collins is in the Fighter's Room, Conan can be seen in the background, and the Australian is missing the wounds he received during the earlier fight.