Orgel / Watch / Moon Phase
The star-shaped locket appeared in the anime, the manga, and PGSM, although it had a slightly different function (and name) in each version of the series. Its very first appearance was in the manga, and its manga incarnation became the model for the anime and PGSM versions of this object.
Who uses it?: Sailor Moon (Princess Serenity), Tuxedo Kamen (Prince Endymion)
In the anime, the orgel was a golden star-shaped locket with a gold chain attached. When the front of the locket opened, it began to play a slow, music box version of Moonlight Densetsu, the Sailor Moon theme song.
The orgel first appeared in episode 026. During the battle with the youma Boxy, Tuxedo Kamen dropped the orgel on the ground (although he didn't realize that he dropped it), and Sailor Moon picked it up. In episode 028, an illustration helped Mamoru to connect the orgel to the princess, although he still did know know who the princess was or where to find her because he could not remember his past. Also in episode 028, he officially gave the orgel to Sailor Moon. In episode episode 035, when Sailor Moon regained her memories of her past life during the Silver Millennium, it was revealed that Princess Serenity originally gave the orgel to Prince Endymion before the battle against the Dark Kingdom.
The final appearance of the orgel in Season 1 occurs in episode 046. Following Queen Beryl's instructions, the brainwashed Endymion attacked Sailor Moon and attempted to kill her. Sailor Moon had been attacked repeatedly and had lost a considerable amount of her strength... she had dropped the Moon Stick and was unable to reach it in order to attack. Instead, she held up the open orgel and begged Endymion to remember his past with her. He hesitated... then reached out to touch the locket. The moment he touched it, the dark energy left him and he regained all memories of Usagi.
Who uses it?: Tuxedo Kamen (Prince Endymion)
Who uses it?: Usagi Mamoru
In Pretty Guardian Sailor Moon, the locket was known as the Moon Phase. Mamoru gave it to Usagi as a gift in Act 36.