Orgel

Rendered as a little star of metal on a chain, the piece conceals a domed middle; lift the dome and a crescent moon sits on a white field, spinning gently and glowing while the melody plays. The word itself is simply the ordinary Japanese name for a music box, and a Bandai toy version circulated under a label English sellers tended to translate as a starry-sky music box. No such locket exists in the manga, where Mamoru's Moon Phase pocket watch, a distinct object, fulfills a similar role; the anime keepsake was actually patterned after that very watch.

Once its lid comes up, the locket sounds an instrumental take on Moonlight Densetsu, casting a slim beam of light as the crescent within turns. Now and then it begins to play with no one touching it, which many read as proof that it answers to the heart of whoever owns it; one such spontaneous tune soothed both Usagi and Naru. Whether any real magic runs through it is never confirmed, but its Moon Kingdom roots and a single dramatic moment hint that way. With Endymion under Beryl's mind control, Sailor Moon reaches for the locket as a desperate final measure, and the instant he makes contact, light pours over him and returns everything he had forgotten.

The locket's earliest keeper is Princess Serenity, who hands it to Prince Endymion as a token of the bond they shared in the Silver Millennium, a moment revisited both in a later flashback and in a canvas painted by Yumemi Yumeno, a former Seven Great Youma who recalled it from a past life. Come the present, Tuxedo Mask holds onto it until a fight knocks it from his grasp and Sailor Moon picks it up, and in time he tells her the treasure is hers to keep.