Urawa Ryo
Urawa has only appeared in Sailormoon twice, but when he appears, we all know he searching after his love Ami. Whenever he comes to visit he's there to see Ami first.
Urawa has a big crush on Ami. He felt she was kind, and very smart, and that he didn't deserve her. However, when Usagi found this out she was able to get the two together. They couldn't stay together very long because his father had business somewhere else, and he left. But before he left, Ami gave him a good picture of her, and waved good-bye to her friend. Ami used this as an excuse cause she was too shy to go out with him.
Urawa was also a carrier of a rainbow crystal which enabled him to see into the future. Because of this power, he knew Ami's true identity, he knew the answers to exams so he could be top score along with Ami, and that Zoisite would one day come after him to take away his Crystal. When Zoisite did, he lost his crystal and became evil, and instructed Ami to destroy him, but she wouldn't and saved him with the help of Sailormoon.
When Beryl tried to revive the crystal Carriers again, Sailormercury came and saved Urawa, and destroyed the black crystal. She then told Urawa of her true feelings for him, and they became boyfriend and girlfriend. After that he left, and never appeared again. In "Ami's 1st love," it was assumed that it was Urawa that was competing with Ami.