Watanabe Rio (渡邊璃生) is a former member of Babyraids JAPAN. She was the youngest of the group.

She is also a writer under the name Kudo Ryo (工藤了).

She retired from Showbiz on May 20, 2021, closing both Twitter accounts on August 20, 2021.

On September 12, 2021, she was a secret guest on the talk show "Metaro's Channel OPENREC", and opened an Instagram account under her alias Kudo Ryo.