Debuted in September 2013 as Shion Utsunomiya (宇都宮しをん).
In September 2015, she transferred from 8Man to T-powers and re-debuted as "RION".
She stopped her activity in September 2018.
In December 2019, she returned to 8man Production under the name "Rara Anzai," which she used during the 2014 Playboy gravure rollout.
She ranked first in adult video sales by actress in the first half of 2020.
She is nick-named as "God of Milk".
Her hobby is swimming.