Mamoru Chiba (called Darien Chiba in the English manga and Darien Shields in the English anime) is Usagi's boyfriend. He uses magic powers to transform into a man named Tuxedo Mask, who fights evil along with the Sailor Senshi. In the future, Usagi and Mamoru get married and become the king and queen of the earth. Their daughter, named Chibiusa (Rini in the English version), travels through time to help them and the Sailor Senshi.