Okamaras is a 'transvestite' Kaiju, with a same-sex attraction of currently indeterminably orientation. The name is a pun of okama; in present day, this term is considered a homophobic slur, and - along with the time in which it was written, along with outdated perceptions of the LGBT+ community - may indicate that Okamaras was intended to be a gay individual. It is possible that Okamaras is potentially transgender, due to Japanese gendered pronouns and speech patterns, as opposed to a cross-dressing individual.
They first appear as the antagonist of the pilot chapter, but they later reappear in the first serialised chapter as one of the invading aliens and again as one of Kinkotsuman's minions. They appear to have a crush on Kinnikuman, and their feelings for Kinnikuman lead them to allow Kinnikuman to escape from Kinkotsuman's prison.
When all other Chojin are busy, Kinnikuman is called upon to stop a group of space kaiju from attacking Earth.  Okamaras is shown on a slideshow to Kinnikuman, but Kinnikuman expresses a confidence in easily defeating Okamaras, but - when the fight is due to take place - Okamaras and the other Kaiju reveal they have returned home, as they do not wish to fight Kinnikuman. 
Later, Kinnikuman is invited to a party in an old manor house, which he attends alone.  Kinnikuman is trapped in a cage, when a group of Kaiju reveal that this was a trap all along and that the women who enticed Kinnikuman to the manor house where kaiju in disguise. They beat Kinnikuman and throw him into a jail cell, but Okamaras appears and expresses relief that Kinnikuman remembers him, before revealing his is in love with Kinnikuman. 
Okamaras helps Kinnikuman to escape by flirting with Iwao, and then - when they notice Kinnikuman running away - spills oil to stop the others from catching up with him, before yelling at him to use his Kinniku Flash. He is relatively unharmed, as he states that his love is stronger than any flames.