Rena Mamiya is the human form of the Uca Worm, the original Rena was a talented singer with a kind heart that wanted to help people. Believing herself to be Rena, she chases after her dream of being an opera singer until her Worm persona eventually resurfaced. She is able to sing one more requiem for Daisuke on stage, expressing her gratitude to him.
Her true form is Uca Worm, the first executive Worm. She has a large claw for the right arm capable to tearing through steel, a shield for the left arm, and has a thick shell.
A cruel and clever planner, she is the one who ordered a Worm to capture (or kill) Juka. In Worm form, she is very powerful and on her first debut, she defeated both TheBee and Drake. She is also the only Worm to "truly" defeat Tendou and make him involuntarily power down. Soon after, she discovers the existence of the Hyper Zecter and attempts to retrieve it after she shoved Renge off a building, only to get caught in an explosion when the hidden bomb within the Hyper Zecter case explodes.
Publication Information
- Worms : Rena Mamiya
- Japanese : 間宮 麗奈
- Type : Worms
- Known As : Uca Worm
- Categories : Executives Worms
- Gender : Female
- HomeWorld : Earth (Main Timeline Continuity)
- Season : Kamen Rider Kabuto
- First Appeareance : Kamen Rider Kabuto Episode 25 : The Proud Searchlight
- Last Appeareance : Kamen Rider Kabuto Episode 40 : The Saddest Battle
- Number of Appeareance : 20 (Kabuto)
- Potrayer : Hitomi Miwa
- Main View : Full Episod
Game Appearances
- Kamen Rider Kabuto Video Game
Form
Uca Worm
- Uca Worm
- Height : 218 cm
- Weight : 117 kg
- Uca Worm, the first executive leader Worm who posed as a woman whose childhood dream was to sing in an opera.

















