- Name: Tamenaga Shion (為永幸音)
- Nicknames: Tame-chan (ためちゃん), Tame (ため), Shionnu (しおんぬ)
- Former Stage Name: OTO♡
- Birthdate: February 9, 2004
- Birthplace: Nagano, Japan
- Height: 149cm
- Hobbies: Power spot tours, drums
- Specialties: Drums, cooking rice
- Looks Up To: Kudo Haruka, Sayashi Riho, Makino Maria, Kishimoto Yumeno, Kamikokuryo Moe
- Hello! Project groups:
- Other groups:
Tamenaga Shion became a member of Beam Idol School in April 2015, and graduated several months later on November 22nd. She made her screen debut in September 2015, playing young Tokiko in the "Suguru Hi no Yamaneko" film. She joined the idol duo ☆ARION☆ on December 24th and continued until the unit's disbandment on December 31, 2016. While she was in the group she also began pursuing solo idol activities under the name OTO♡.
Tamenaga participated in the "Morning Musume '16 Shinseiki Audition", but failed to pass the third round. She ceased solo OTO♡ activities on October 31, 2017. Prior to halting her activities, over the summer of 2017 she became a finalist in the "Hello! Project Shin Member Audition". When it was announced that no winners would be chosen from the audition, she and several other finalists accepted an invitation to join Hello Pro Kenshuusei. They made their first live appearance and were officially introduced at the "Hello! Project Kenshuusei Happyoukai 2017 12gatsu ~Conti→New!~" concert on December 10, 2017.
Tamenaga received the Dance Award for her performance of Goto Maki's "Daite yo! PLEASE GO ON" at the "Hello! Project Kenshuusei Happyoukai 2020 ~Natsu no Koukai Jitsuryoku Shindan Test~" event on July 26, 2020.
On November 2, 2020 Tamenaga was revealed to be one of three new ninth generation members of ANGERME, alongside audition winners Kawana Rin and Matsumoto Wakana. The reveal was made through a special premiere on the official group YouTube channel. During the reveal her member color was also announced to be pink. Their first performance as part of the group would take place on December 9, 2020 at sixth generation member Funaki Musubu's graduation concert, titled "ANGERME Concert 2020 ~Kishoutenketsu~ Funaki Musubu Sotsugyou Special".
-  Suguru Hi no Yamaneko (過ぐる日のやまねこ) (as young Tokiko)
- TV Programs
-  Shoujo-tachi no Ketsudan ~Mitchaku!! Hello! Project 20th Anniversary Audition~ (少女たちの決断〜密着!!ハロー!プロジェクト20周年オーディション〜)
-  Hello Pro no Oshigoto Challenge! 2 (ハロプロのお仕事チャレンジ!2)
- Music Videos
- Made her first live appearance at the "Hello! Project Kenshuusei Happyoukai December 2017 ~Conti→New!~" event on December 10, 2017.
- Was formerly a member of local indie idol groups Beam Idol School (graduated on November 3, 2017) and ☆ARION☆ (group disbanded 2016), and pursued independent idol activities under the name OTO♡ until October 31, 2017.
- Participated in the 2016 Morning Musume '16 "Shinseki" Audition, but did not pass the third round.
- Was a finalist in the 2017 Hello! Project New Member Audition; her number was #113. No finalists passed the audition.
- Knows some tate (殺陣; a type of sword-based stage combat).
- Is learning how to play drums on a home drum-kit with her grandfather; she gives him lessons, and he jokes about having a scary teacher.
- Thinks her charm points are her long fingers and the way her eyes crinkle when laughing.
- Her favorite genre of music is J-Pop.
- Her favorite sports are dance, long distance running, soccer, and dodgeball.
- Her motto is "Egao wa hito wo shiawase ni" (笑顔は人を幸せにする; A smile makes people happy).
- Her favorite food is tarako spaghetti.
- Her favorite sweets are tea-based sweets.