Genta Umemori: The Sushi Samurai
Genta Umemori would be what I'd call a secondary comic relief after Ryunosuke's hammy reactions or Chiaki's slacking. So he was just appearing as a mysterious sushi seller with unusual antics who turned out to have some unusual gifts in handling mojikara, a funny attitude and of course he was Takeru Shiba's best friend as a child. So he always interrupted Takeru's training to where he obviously got the Ika Origami, and he managed to train himself hard and he became from a samurai wannabee to a modern day samurai despite the fact he came from a line of sushi sellers. His return to the present was of course hilarious. My only issue was that seldom, the actor Keisuke Sohma felt like Felix Ryan (Spike's actor in PR Samurai) in his acting but I wouldn't say its horrid, at least he's a comic relief with plot contribution.
While trying to join the Shinkengers in the most comical of methods, he was initially denied by his childhood friend to keep him safe. However, he was able to prove his worth and his need especially with his talent in mojikara allowed some rather cool upgrades. For instance, he created his own Ebi Origami and unlocked the secrets of the Black Box. Also, he created Daigoyou during the time he turned into a coward because he was swapped with a sushi and nearly eaten by a cat, until he was cured. But this didn't stop him from being a comic relief as always, he was a goofy guy who may rival Ryunosuke's hammy reaction.
Things were put to the test whenever his friend Takeru's life was in danger which showed he can also get serious when needed. Eventually, he showed much of his worth when the truth about Takeru being a shadow warrior to protect Kaoru from harm was revealed. She saw the worth in Kaoru and they fought side by side in order to carry out the job that was needed. In the finale after a rather tough battle, he goes to France where hopefully, he's learned to cook French as well with his magic fingers. Oh yeah, he could also teach Mako a thing or two so she can improve.