Mamoru Chiba, alias Tuxedo Mask, originates as the reincarnation of Prince Endymion, sovereign of Earth’s Golden Kingdom during the Silver Millennium. His current life is shaped by tragedy: orphaned in a car accident on his sixth birthday, he suffers retrograde amnesia, severing ties to his royal past. Haunted by fragmented memories, he experiences recurring visions of an enigmatic woman compelling him to seek the Silver Crystal. This quest drives him to don the Tuxedo Mask persona, initially unaware of its ties to his lineage. Clad in a black tuxedo, cape, and mask, he wields roses as both projectiles and tokens of safeguarding. Transformation mechanics differ across media: the anime shows spontaneous shifts triggered by Sailor Moon’s danger, while the manga depicts deliberate rituals with a rose and stylized sequences. Though lacking direct combat prowess akin to the Sailor Guardians, his powers encompass psychometry, healing, and energy projection, anchored by the Golden Crystal—Earth’s life-force conduit. He stabilizes Sailor Moon’s Silver Crystal, magnifying its power during pivotal conflicts. His dynamic with Usagi Tsukino (Sailor Moon) begins with playful antagonism, marked by teasing monikers like “Bunhead,” before unfolding into a romance echoing their past identities as Princess Serenity and Prince Endymion. Their bond withstands brainwashing by the Dark Kingdom, mutual memory loss, and apocalyptic prophecies foretelling catastrophe if they unite. A self-imposed separation during the Black Moon Clan arc resolves only after confronting future selves and reaffirming their timeless devotion. Media adaptations diverge in his portrayal: the 90s anime leans into aloofness and tough-love mentorship toward Usagi, while the manga emphasizes introspective support. The live-action *Pretty Guardian Sailor Moon* introduces an engagement to Hina Kusaka, honoring a childhood vow devoid of romance, before he fully embraces his Endymion mantle to aid the Guardians. Vulnerable to manipulation by antagonists like Queen Beryl and Sailor Galaxia, he often requires rescue by Usagi. His future incarnation, King Endymion, orchestrates temporal interventions to safeguard their daughter Chibiusa and test his resolve. In *Sailor Moon Eternal*, disruptions to the Golden Crystal sicken him, linking his fate to Earth’s core, Elysion, until Usagi and Chibiusa restore balance. As a civilian, Mamoru pursues medicine, mirroring his healing gifts, and enjoys reading and track sports. His anime wardrobe draws humor for clashing hues, contrasting regal manga depictions as Prince and King Endymion—the latter adorned in a white tuxedo and lavender cloak during the Dream arc. His arc navigates protection, sacrifice, and the tension between destiny and choice. From a solitary amnesiac to a steadfast partner and protector, he balances fragility and fortitude, anchoring both Earth’s defense and Usagi’s evolution.