S/he is a character of unknown gender and background. Boss contacts Minako and Artemis through the Transformation Pen and gives instructions, advice and information about the enemy. It is unknown who Boss truly is.
Boss did not appear in any other part of the Sailor Moon franchise, and was never referred to in the Sailor Moon manga. The true identity of Boss was never revealed.
- Fans have theorized that Boss could be Queen Serenity or Luna. If following the canon of Pretty Guardian Sailor Moon, however, this is not possible.