Washio Reina was born on January 20, 1994 in Saga Prefecture, Japan.
Prior to auditioning to LDH, she was a trainee of EXPG Fukuoka since her first year of high school. Washio dropped out from school at the first year of high school to focus on becoming a singer. In 2011, Washio applied to EXILE Presents VOCAL BATTLE AUDITION 3 ~For Girls~ in the vocal section.
On July 26, during an E-Girls SHOW event in SHIBUYA-AX, it was revealed that Washio was one of the winners of the VOCAL BATTLE AUDITION 3 and was added to FLOWER as a vocalist. On that same day, she was also added as a member of E-girls, having a concurrent position between the group and FLOWER.
On October 12, she made debut with FLOWER with the single "Still".
- Main article: List:Washio Reina Discography Featured In
- [2013.08.14] DJ DECKSTREAM - DECKSTREAM.JP (#12 Ano Hi no Sayonara feat. Washio Reina (Flower / E-girls))
- [2014.03.26] m-flo - FUTURE IS WOW (#12 d.w.m / m-flo + Reina Washio (Flower / E-girls))
- [2018.06.20] MACO - BEST LOVE MACO (#3 Dear My Friend feat. Washio Reina (E-girls / Flower))
- Solo Songs
-  Hitohira
- Main article: Washio Reina/Gallery
- Favorite artists: JUJU, Amuro Namie, Crystal Kay
- Favorite movies: Harry Potter, Meitantei Conan
- Favorite food: Nattou (Fermented soybeans)
- Favorite flower: Sunflowers
- Hobbies: Karaoke, Watching music videos, Gaming
- She is currently the only member to be vocally featured on all E-girls' a-side singles.
- She revealed on the TV show EG-style that one of her dreams is for E-girls do a dome tour and Flower do an arena tour.
- She started an Instagram account on July 27, 2017.
- She has a very good friendship with singer MACO. Their pairing name is called Washimaco (わしまこ). She also collaborated in MACO's song "Dear My Friend", released in June 2018.
- Her fans gave her the nickname Reichieru (れいちぇる). EXILE HIRO often calls Washio by the nickname Wasshi (わっしー).
- Former AKB48 member Maeda Atsuko revealed to be a fan of Washio and attended Flower's Flower LIVE TOUR 2015 "Hanadokei" on June 26 in Zepp Tokyo.
Oldest Member of E-girls
- ↑ Ｅ―ｇｉｒｌｓ鷲尾伶菜、きつくても波乱万丈でも選んだ道が自分の正解
- ↑ “EXILEの妹分”新生FLOWER、5人加入し9人体制で10月デビュー
- ↑ 鷲尾伶菜「LARME」に初登場「E-girlsとは違った一面」
- ↑ 鷲尾伶菜からファンの皆様へ
- ↑ MACOとFlower鷲尾伶菜の“わしまこ”が仲良く「さしめし」
- ↑ 6.0 6.1 前田敦子、Flower鷲尾伶菜は「全てがどストライク」 豪華タッグに「最高の2人」の声
- ↑ http://archive.is/20151006074155/http://7gogo.jp/talks/ejH8omPfQGcc/3804
- ↑ https://twitter.com/Atsuko_100/status/614492282570436609