- Birthday: July 18
- Age: Unknown
- Joined: November 2016
- Previous groups: SiS
- Previous names: Michihayashi Rio (Audition name) / Coco Chanel (SiS name)
Her mother was a model and a former yankee (delinquent)
She went to a rich, all girls school in Nagoya, where she grew up. Her house always had a climbing frame in the garden.
She attended college for a year before audition for the reformed BiS audition.
She loves the Sanrio character Tuxedo Sam.
Originally auditioned for the reformed BiS. On being unsuccessful she was placed into SiS before being merged with GANG PARADE.
On 2017 during WACK Elections, Watanabe said that if she came last on ranking she would have to run a 100km marathon. Later during the appeals she declared that she would also run a 100km marathon if she came first. She ranked 11th and eventually after the event she announced she would run the marathon anyway. The 100km marathon took place on February 7th 2018 from Atami to Hanzomon studio where the other members were waiting. During the 24 hours a live stream was held showing both Coco running and the other 6 members on the studio.