He was the son of Misaka Kuramitsu and assumingly the heir to the powerful Kuramitsu family.
Mikamo met and fell in love with Washu at the Galaxy Academy while it was still the Jurai Imperial Academy and located on Juraian territory. As he was from Seniwa, Jurai's rival planet, he took on the name Mikamo Niwase. He and Washu married and had a son named Mikumo.
As revealed in the True Tenchi novels, Mikamo's grandfather was the Chairmen of Seniwa's High Council and wished to open Seniwa, but died before he could do so. Misaka opposed the opening of Seniwa and ordered Mikamo to return home so that no supporters of opening the planet would know he had been away. As Washu was of common status, he had to leave her and take Mikumo with him. After this Mikamo married a woman named Koyori and gained a stepdaughter, Miyuki. Mikumo later married his stepsister and together are the great-grandparents of Mihoshi Kuramitsu.
Mikamo possessed the ability to get almost anywhere, much like his great-granddaughter, Mitoto, and his great-great-granddaughter Mihoshi, an ability they most likely inherited from him, though it is unknown if he was as ditzy as his two descendants.
Mikamo was also a student of the Galactic Academy for a time, and studied under Washu prior to their developing a romantic relationship, indicating a likely high degree of intelligence.