The Takenouchi family and the Umenouchi family are two clans on the dark side of the moon that have been divided for many years. Kaguya, daughter of Fumiya, is next in line to become queen but she refuses to follow the rules and wishes to live her life freely. Her mother, Queen Fumiya, has been ill for a long time and has kept it hidden from Kaguya to protect her. However, when Fumiya's condition worsens, the Umenouchi family takes advantage of this opportunity to seize control of the government. In order to ensure her daughter's safety on the moon, Queen Fumiya sends Kaguya to Earth with a powerful katana that represents her ownership of the moon. Without the sword, the Umenouchi family cannot take over the moon. This forces Kaguya to grow stronger and mature in order to reclaim what was once her mother's.
Gekka Bijinhas been published in English as Blade of the Moon Princess by VIZ Media under the Shonen Jump imprint since September 5, 2023.