Yuichi Nakamura is a close friend to a fellow voice actor Tomokazu Sugita, as both even shared the same apartment. So much that in one point, when a fan approaches Tomokazu, he would bluffing his name under Yuichi's.
Ironically, despite both being best friends, some of their voice acting roles involve their characters fighting against each other. Yet, if compared to their respective roles in the Ultra Series, Ultraman Ginga and Ultraman X, both Ultramen had contradicting personalities, with Ginga being quiet, calm and stoic while X is that kind of talkative, pushy and albeit hot-blooded.
Yuichi is known to be acrophobic (fear of heights), a trait that was shown by Ultraman X's host, Daichi Ozora.
The only difference in spelling of their names is in the kanji used. Yuichi the actor contains the kanji 優, which, incidentally, means "actor", while the voice actor Yuichi's name uses the kanji 悠, which means "long time".