I'm sure it's got nothing to do with Lunar besides the name but their site went into detail about where the name Hiro comes from.
According to their website:
http://www.nonisportsdrinks.com/about-noni-hiro.php"Hiro, an ancient Polynesian warrior, lived in the 12th Century was from the sacred island of Raiatea. A direct descendent of the creator gods Taaroa and Oro, Hiro was a giant of a man, known as the biggest man of his day. The legend of Hiro speaks of him as wise and strong, who prided himself in doing things others could not. Hiro formed rocks from sand to protect his islands, made fire, built the grandest ship of his day, spread Polynesian culture to other islands, and was the conqueror of his world!"
I'm curious if they took this into consideration (at all) with the Lunar 2 character's name or if it's a play on "hero."