Prior to joining Hello! Project, she was active as a Nagano local idol.
Tamenaga Shion was born on February 9, 2004 in Nagano, Japan.
In September 2015, Tamenaga made her acting debut in the Suguru Hi no Yamaneko film, portraying the childhood version of Tokiko.
On December 24, 2015 she joined the duo idol group ☆ARION☆, and stayed in the group until its disbandment on December 31, 2016. While in ☆ARION☆, she also began pursuing solo activities under the name OTO♡.
In 2016, Tamenaga participated in Morning Musume '16 Shinseiki Audition, but failed to pass the third round.
On October 31, she ceased activities as OTO♡.
Over the summer, Tamenaga participated in the Hello! Project Shin Member Audition for a chance to join Hello! Project in commemoration of its 20th anniversary, and made it to the finals alongside seven others before it was ultimately decided that no one would pass the audition.
Following the audition, Tamenaga accepted an invitation to join Hello Pro Kenshuusei. She was introduced alongside six other finalists at the Hello! Project Kenshuusei Happyoukai 2017 12gatsu ~Conti→New!~ show on December 10.
On April 4, she participated in a fanclub event titled Hello Pro Kenshuusei Special Event in Nagoya ~Hajimemashite! 3~ at Midland Square Cinema 2 alongside Yonemura Kirara, Hashisako Rin and Shutto Anna.
Tamenaga participated in the opening act and challenge act for the Morning Musume '19 Concert Tour Haru ~BEST WISHES!~.
On July 26, Tamenaga won the judge's dance award at the Hello! Project Kenshuusei Happyoukai 2020 ~Natsu no Koukai Jitsuryoku Shindan Test~ event for her performance of "Daite yo! PLEASE GO ON".
As of April 2020, Tamenaga is in her first year of high school.
Here is a list of nicknames that was used to refer to Tamenaga Shion:
- Name: Tamenaga Shion (為永幸音)
- Former Stage Name: OTO♡
- Nicknames: Tamechan (ためちゃん), Shion-chan (しおんちゃん), Shionnu (しおんぬ), Tame (ため)
- Birthdate: February 9, 2004
- Birthplace: Nagano, Japan
- Blood Type: Unknown
- Height: 153cm
- Western Zodiac: Aquarius
- Eastern Zodiac: Monkey
- Hello! Project Status:
- 2017-12-04: Hello Pro Kenshuusei member
- UP-FRONT PROMOTION Status:
- 2017-12-04: Member
- Hello! Project Groups:
- Hello Pro Kenshuusei (2017-)
- Other Groups:
- Beem Idol School (2015)
- ☆ARION☆ (2015-2016)
- Special Skill: Drums, cooking rice
- Hobbies: Comedian appreciation
- Charm Point: Her thin fingers
- Favorite Music Genre: Jpop
- Favorite Food: Tarako spaghetti
- Favorite Color: Yellow
- Motto: "A smile makes people happy" (笑顔は人を幸せにする)
- Favorite Hello! Project songs: Maji Desu ka Ska!, Shabondama, Nakenai ze・・・Kyoukan Sagi
- Looks Up To: Makino Maria, Sayashi Riho
- [2020–] Hello Dream.
-  Shoujotachi no Ketsudan ~Mitchaku!! Hello! Project 20 Shuunen Audition~ (AbemaTV)
- [2017-] Hello! Project Station
-  Hello Pro no Oshigoto Challenge! 2
-  Suguru Hi no Yamaneko
- She knows some tate (殺陣; a type of sword-based stage combat).
- She and her grandfather are learning how to play the drums, and they practice on their home drum-set.
- She gives her grandfather drum lessons, and he jokes that his teacher (Shion) is scary.
- She was an extra in Little Glee Monster's "Jinsei wa Ichidokiri" music video, as the girl wearing a blue shirt and red backpack.
- She can't make up her mind on what to eat from the menu at a restaurant.
- She loves cooking her own healthy meals like konnyaku and cream omurice.
- Gallery:Tamenaga Shion
- List:Tamenaga Shion Discography Featured In
- List:Tamenaga Shion Concert & Event Appearances
- ↑ 1.0 1.1 1.2 1.3 1.4 1.5 1.6 1.7 "【ハロ！ステ#284】ひなフェス2019！BEYOOOOONDS＆カントリー・ガールズLIVE、ハロプロ研修生紹介Movie、こぶしファクトリー最新MV公開！ MC：浅倉樹々＆前田こころ" (in Japanese). Hello! Project Station (via YouTube). 2019-4-10.
- ↑ "はじめまして☆彡" (in Japanese). Beem Idol School Official Blog. 2015-05-02.
- ↑ "みなさまへご報告" (in Japanese). Beem Idol School Official Blog. 2015-11-21.
- ↑ "感謝の気持ちを込めて…" (in Japanese). OTO Official Blog. 2017-10-31.
- ↑ Shoujotachi no Ketsudan ~Micchaku!! Hello! Project 20 Shuunen Audition~ Episode #1. AbemaTV. 2017-11-13.
- ↑ Shoujotachi no Ketsudan ~Micchaku!! Hello! Project 20 Shuunen Audition~ Episode #6. AbemaTV. 2017-12-04.
- ↑ "ハロプロ研修生に新メンバーが加入！" (in Japanese). Hello! Project. 2017-12-11.
- ↑ http://www.helloproject.com/news/12197/
- ↑ "13回目の「ママありがとうの日」" (in Japanese). OTO Official Blog. 2017-02-09.
- ↑ Hello Dream. Episode 7.