- Name: Okai Chisato (岡井千聖)
- Nicknames: Chisato (ちさと), Chippe (ちっぺ), Chissaa (チッサー)
- Birthday: June 21, 1994
- Birthplace: Tokorozawa, Saitama, Japan
- Blood type: A
- Height: 149cm
- Hello! Project groups:
It was announced in October 2010 via Ustream that she would be releasing her first photobook and DVD in late December.
The disbandment of °C-ute was announced on August 20, 2016 through various online and print news sources, followed closely by the official website and blogs of the members. The last performance for the group was scheduled to take place in June 2017 at Saitama Super Arena, during their 12th year of activities.
On May 27, 2017 Okai Chisato announced that after the group disbandment she intended to mainly focus on variety and talk shows but would make a return to singing at some point in the future.
- [2011.01.25] Romantic Ukare Mode (ロマンティック 浮かれモード)
- [2010.12.27] LOVE Namida Iro (LOVE涙色) (Matsuura Aya cover)
- [2011.01.23] Romantic Ukare Mode (ロマンティック 浮かれモード) (Fujimoto Miki cover)
- [2011.03.29] Furusato (ふるさ) (Morning Musume cover)
- [2011.03.29] Manatsu no Kousen(真夏の光線 ) (Morning Musume cover)
- [2011.03.29] Egao ni Namida ~THANK YOU! DEAR MY FRIENDS~ (笑顔に涙~THANK YOU! DEAR MY FRIENDS~) (Matsuura Aya cover)
- [2010.12.22] Chissaa (ちっさー)
- [2011.02.25] Solo Live 2011 Vol.1 ~Kaisha de Odottemita!~ Live in Heaven (会社で踊ってみた)
- [2011.04.18] Solo Live 2011 Vol.2 ~Hanzomon de Odottemita!!~ (半蔵門で踊ってみた)
- [2011.12.09] IMP. GIRL
Compilations / Other
- [2006.12.13] Morning Musume - 7.5 Fuyu Fuyu Morning Musume Mini! (#4 Samui Kara Fuyu da mon! ~Doumokou mo Naissu yo Mikitty~ - Fujimoto Miki with Okai Chisato, Hagiwara Mai)
- [2010.12.24] Chisato (千里)
-  Koinu Dan no Monogatari (仔犬ダンの物語)
-  Hotaru no Hoshi (ほたるの星)
-  Ousama Game (王様ゲーム) (as Maruoka Kaori)
-  Gomennasai (ゴメンナサイ)
- TV Dramas
- TV Programs
- [2002–2007] Hello! Morning (ハロー! モーニング)
- [2006–2007] °C-ute has come.
- [2007–2008] Haromoni@ (ハロモニ@)
-  Berikyuu! (ベリキュー!)
- [2008–2009] Yorosen! (よろセン!)
- [2010–2011] Bijo Gaku (美女学)
- [2011–2012] HELLOPRO! TIME (ハロプロ！ＴＩＭＥ)
- [2012–2013] Hello! SATOYAMA Life (ハロー！ＳＡＴＯＹＡＭＡライフ)
- [2013–2014] GOGO! Smile! (ゴゴスマ)
- [2014–] The Girls Live
- [2014–] Haraichi no Kami Apuri @ Ryuuseiki~ON LINE~ (ハライチの神アプリ＠隆盛紀~ＯＮ ＬＩＮＥ~)
-  °C-ute no Challenge TV (°C-uteのチャレンジTV)
- [2014–] Afro no Hen (アフロの変)
- [2015–] Chou Shiritoriaru (超シリトリアル)
- [2017–] Panther no Keirin Hajimemashita (パンサーの「競輪、はじめました。」)
-  BS-TBS
- Music Videos
-  Buono! - Honto no Jibun (ホントのじぶん)
-  Team Okai - Wakuteka Take a chance (ワクテカ Take a chance) (as Sayashi Riho)
- [2010–] Okaichan, Neru! (岡井ちゃん、寝る!)
-  Michishige Sayumi no "Mobekimasutte Nani??" (道重さゆみの『モベキマスってなに？？』)
-  1974 (Ikunayo) (1974(イクナヨ))
-  Sengoku Jieitai (戦国自衛隊)
-  STRONGER (ストロンガー)
-  Theater in The Round (青山円形劇場)
-  Sakura no Hanataba (さくらの 花束)
- Radio Dramas
-  Tokai no Hitorigurashi (都会の一人暮らし)
- Her official image color is green. Prior to Umeda Erika's graduation in 2009, her image color was blue.
- Has two younger sisters and a younger brother. Her sister Asuna was a member of Hello! Pro Egg.
- Is good friends with Hagiwara Mai, Nakajima Saki, and Tsugunaga Momoko.
- Her favorite Berryz Kobo member is Natsuyaki Miyabi.
- Has said Fujimoto Miki is the Hello! Project member she respects the most.
- Has two dogs and a turtle.