Mamoru Chiba is Usagi Tsukino's primary romantic interest and boyfriend. He is a second year student at Moto-Azabu Private High School. He lives by himself in an apartment building in Tokyo. Mamoru believes that the Silver Crystal will help him regain his memories. After having the same dream over and over filled with one phrase "The legendary Silver Crystal" he found himself roaming the streets at night, searching for the Crystal.
Mamoru Chiba was in a car accident when he was 6 and lost his parents as well as his memories. As the only survivor, he grew up in an orphanage ever since with amnesia.
Mamoru has short neat black hair and deep blue eyes. He usually wears formal attire and occasionally glasses. Though, the glasses don't appear often as he doesn't need them. He usually has a neutral face, making it hard to tell what he's thinking. He stands at about 175 cm or 5 feet 9 inches.
When Usagi is upset about her grade on her last English test, she crumbles up the paper and throws it behind her, not realising Mamoru was standing behind her. He complains to her, while making fun of her hairstyle and throws her test back at her. Usagi begins to complain to him, and they suddenly stare at each other in awe. Mamoru gives Usagi her test back and she walks off, thinking how her heart is beating faster, though outwardly complaining how strange it is that he was wearing a tuxedo in the afternoon. Mamoru then acknowledges the Jewellery store, OSA-P, wondering if it might have the mighty Silver Crystal he is seeking.
Mamoru is capable of healing without needing to transform. He is also capable of having premonitions of impending danger. Mamoru shares a strong telepathic connection with Usagi. With some effort, he can directly communicate with her without a communication device. When Chibiusa lost her soul to Mistress 9, her heart stopped beating and Mamoru linked his own vital energy with her to keep her body alive until her spirit was returned.