Eguchi Saya was born on August 1, 2003 in Hyogo, Japan.
On March 6, it was announced that Eguchi had joined Hello Pro Kenshuusei alongside Shimakura Rika, Hibi Marina, Doi Rena, Okamura Minami, Matsunaga Riai, Yamada Ichigo, and Nakayama Natsume. She was introduced at the Hello! Project Kenshuusei Happyoukai 2017 3gatsu ~Marching!~ on March 11.
On June 9, during the Hello! Project Kenshuusei Happyoukai 2018 6gatsu ~Niji~ in Tokyo, it was announced that Eguchi was chosen alongside Nishida Shiori and Shimakura Rika to join the new group led by Ichioka Reina that would debut later in 2018.
On October 19, the name of the group led by Ichioka was announced as CHICA#TETSU. It was also announced that it would be part of the combined group BEYOOOOONDS alongside the second group Ame no Mori Kawa Umi and a third group formed by the Hello! Project "ONLY YOU" Audition winners.
On July 30, Eguchi celebrated her 16th birthday at a fanclub event titled BEYOOOOONDS / CHICA#TETSU Eguchi Saya Birthday Event 2019 with two shows at LANDMARK HALL.
On November 5, Nishida Shiori and Eguchi Saya became regulars in a new regular corner on the FM Osaka idol radio show J3 Tuesday~Midnight IQ~ (idol quest), titled "J3 Tuesday~Midnight IQ~ Madamada Kayoubi~yonds! BEYOOOOONDS QUEST!".
On August 4, she celebrated her 17th birthday at a fan club event titled BEYOOOOONDS / CHICA#TETSU Eguchi Saya Birthday Event 2020 with two shows at Shinjuku ReNY. In compliance with government policy, cheering, crowding, standing, and closeness in the venue were prohibited, and wearing masks were required to enter.
She has a pet dog named Melmo.
When Eguchi joined CHICA#TETSU, she was in her third year of middle school. She graduated from middle school in March 2019 and began high school the following April. As of April 2020, she is currently attending her second year of high school.
The following list are notable friendships Eguchi Saya has acquired:
- Name: Eguchi Saya (江口紗耶)
- Birthdate: August 1, 2003
- Birth place: Hyogo, Japan
- Blood Type: O
- Height: ~167cm
- Western Zodiac: Leo
- Eastern Zodiac: Goat
- Hello! Project Status:
- UP-FRONT PROMOTION Status:
- 2017-03-06: Member
- BEYOOOOONDS / CHICA#TETSU Member Color: Daisy
- Hello! Project Groups:
- Other Groups:
- Special Skills: Dance, piano, back bridge
- Hobbies: Singing songs, playing various instruments
- Favorite Music Genres: J-pop, Western music
- Favorite Sports: Tennis, badminton
- Favorite School Subject: Physical education
- Motto: Doryoku wa subete no tobira wo hiraku (努力は全ての扉を開く; Effort opens up all doors)
- Favorite Food: Macaroons, Mont Blanc, buri and hamachi (Japanese amberjack and young Japanese amberjack)
- Favorite Color: Dark Pink
- Charm Point: Her long and curled eyelashes
- Favorite Hello! Project songs: Are you Happy?, The Vision
- Looks Up To: Suzuki Airi
-  Attack No.1
-  Fushigi no Kuni no Alicetachi
-  Reborn ~13nin no Tamashii wa Kami-sama no Yume wo Miru~
-  Arabeyooooonds Nights
- [2018–2019] The Girls Live
- [2019–2020] AI・DOL PROJECT (AI・DOL プロジェクト)
-  KURAGAE ~Watashitachi no Koto, Oshite Kudasai!~ (KURAGAE –私たちのこと、推してください！-)
- [2020–] Uta-navi! (うたなび！)
-  Hello! Project presents... "Solo Fes!"
- [2017–] Hello! Project Station
- [2018–] Upcoming
- [2018–] tiny tiny
- [2018–] OMAKE CHANNEL
- [2019–2020] Hello Pro no Oshigoto Challenge
-  Hello Pro Kouhaku Taiko THE☆BATTLE 2019
- She can play a Jaw Harp.
- She can do a reverse bridge and the "Love take it all" dance.
- She can dance the samba.
- Gallery:Eguchi Saya
- List:Eguchi Saya Discography Featured In
- List:Eguchi Saya Concert & Event Appearances
- List:Eguchi Saya Pocket Morning Weekly Q&A
Youngest Member of CHICA#TETSU
- ↑ 1.0 1.1 "Ikuta Erina Instagram. 2020-07-12.
- ↑ https://ameblo.jp/beyooooonds-chicatetsu/entry-12435645406.html
- ↑ "ハロプロ研修生に新メンバーが加入！" (in Japanese). Hello! Project. 2017-03-06.
- ↑ Yamagishi Riko. ""発表！"山岸理子" (in Japanese). Tsubaki Factory Official Blog. 2018-06-09.
- ↑ "新グループ、グループ名決定のお知らせ" (in Japanese). Hello! Project. 2018-10-19.
- ↑ "ハロー！プロジェクト新グループ、グループ名決定のお知らせ" (in Japanese). Hello! Project Station (via YouTube). 2018-10-19.
- ↑ http://www.fmosaka.net/_ct/17315312
- ↑ "★ファンクラブ会員限定イベント★「BEYOOOOONDS/CHICA#TETSU 江口紗耶バースデーイベント2020」開催決定！" (in Japanese). UP-FC. 2020-07-07.
- ↑ Eguchi Saya. "♡チョコ！♡江口紗耶" (in Japanese). BEYOOOOONDS / CHICA#TETSU Official Blog. 2019-02-07.
- ↑ Eguchi Saya. "♡卒業式！♡江口紗耶" (in Japanese). BEYOOOOONDS / CHICA#TETSU Official Blog. 2019-03-20.
- ↑ Eguchi Saya. "♡新元号！令和！！♡江口紗耶" (in Japanese). BEYOOOOONDS / CHICA#TETSU Official Blog. 2019-04-01.
- ↑ "アイドルニュータイプ現る「ハロプロの最終兵器」BEYOOOOONDSインタビュー（２）" (in Japanese). ENTAME next. 2019-04-17.
- ↑ "BEYOOOOONDS FCイベント2018 ~冬の陣ZIN ~" (in Japanese). Suzuki Keita Official Blog. 2018-12-03.
- ↑ BOMB gravure magazine (September 2018)
- ↑ TV TOKYO's 音流～ONRYU～ 2019.07.26 Episode
- ↑ Hello! Project Kenshuusei Happyoukai 2017 12gatsu ~Conti→New!~ MC.
- BEYOOOOONDS / CHICA#TETSU Official Profile
- BEYOOOOONDS / CHICA#TETSU Official Blog
- Hello Pro Kenshuusei Profile (archived)
|BEYOOOOONDS / CHICA#TETSU||Ichioka Reina (Leader) | Shimakura Rika | Nishida Shiori | Eguchi Saya|
|BEYOOOOONDS / Ame no Mori|
|Takase Kurumi (Leader) | Maeda Kokoro | Yamazaki Yuhane | Okamura Minami | Kiyono Momohime|
|BEYOOOOONDS||Hirai Miyo | Kobayashi Honoka | Satoyoshi Utano|
|Major Singles||1. Megane no Otoko no Ko / Nippon no D・N・A! / Go Waist|
|Other Singles||Collaborations: YEAH YEAH YEAH / Akogare no Stress-free / Hana, Takenawa no Toki|
|Concerts & Events|
|Other Concerts & Events|
|Hello! Project Concerts|
|Units & Other Acts|
|Associated Acts||Hello Pro Kenshuusei|