A key (鍵, Ken) is an item that helps a person access "the true power of the planet Jurai" through a Royal Tree. It helps bond the user (usually members of the Juraian Royal Family) with a tree, not allowing any one else to use it without permission. The key is made by processing the sap from one of the branches of a royal tree, then converting it into jewelry or other shapes. The key assists in accessing the Light Hawk Wings, the most powerful force in the universe.
A master key (マスター キー, Masutaa Kii) is created from the first generation Royal Trees and have the power to control all treeships. First generation keys can harness the exceedingly powerful Light Hawk Wings in order to create a light sword (ex: sword Tenchi), while the keys of younger trees can't.
- Main article: Tenchi-ken
Normal keys (ノーマル キー, Noomaru Kii) are keys made from trees that were grown after the first generation of trees. The keys can create Light Hawk Wings as a defense mechanism for the person, but they cannot create a light sword. Master keys are far more powerful and can bypass normal keys.