Maro is an ancient saints' name -- he was an Italian follower of St. Flavia and was martyred -- rarely used in modern life. The name Maro may stem from the Roman Marcellus, related to Mars, the god of war, or it may be a feminine form of Maria, connected with Mario. Maro is also a Japanese name meaning "myself."
And why couldn't Maro be more widely used today? As a masculine spin on stylish Mara, it certainly could.