|This article is about a/an villian in Kamen Rider Kabuto.|
|Season:||Kamen Rider Kabuto|
|First Appearance:||The Proud Searchlight|
|Last Appearance:||The Saddest Battle|
|Number of Episode|
Rena Mamiya/Uca Worm (間宮 麗奈／ウカワーム, Mamiya Rena/Uka Wāmu) is the first executive leader Worm assuming the form of Rena Mamiya, a woman whose childhood dream was to sing in an opera.
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. 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.