Why Did the Important Memories Disappear?

Why are the Important Memories Disappeared? (大切な記憶はどうして消されたのか) is the thirty-first episode of Kamen Rider Drive.

Cast

 * Shinnosuke Tomari (泊 進ノ介): Ryoma Takeuchi (竹内 涼真)
 * Kiriko Shijima (詩島 霧子): Rio Uchida (内田 理央)
 * Chase (チェイス): Taiko Katono (上遠野 太洸)
 * Go Shijima (詩島 剛): Yuu Inaba (稲葉 友)
 * Jun Honganji (本願寺 純): Tsurutaro Kataoka (片岡 鶴太郎)
 * Rinna Sawagami (沢神 りんな): Rei Yoshii (吉井 怜)
 * Kyu Saijo (西城 究): Kenta Hamano (浜野 謙太)
 * Genpachiro Otta (追田 現八郎): Taira Imata (井俣 太良)
 * Mitsuhide Nira (仁良 光秀): Kisuke Iida (飯田 基祐)
 * Narration (ナレーション), Drive Driver's voice (ドライブドライバーの声): Chris Peppler (クリス・ペプラー)
 * Brain (ブレン): Shota Matsushima (松島 庄汰)
 * Heart (ハート): Tomoya Warabino (蕨野 友也)
 * Medic (メディック): Fumika Baba (馬場ふみか)
 * Freeze Roidmude (フリーズロイミュード)/"Soichi Makage" (真影 壮一): Masami Horiuchi (堀内 正美)

Guest cast

 * Toru Fujiki (藤木 徹): Daisuke Sawamura (澤村 大輔)
 * Iwao Fujiki (藤木 巌): Jin Hirao (平尾 仁)
 * Toru Fujiki's Mother: Tomoko Abe (阿部 朋子)
 * Makage's Assistant: Kiyoshi Ishii (石井 淳)

Shift Cars & Signal Bikes

 * Car Used:
 * Type Change: Shift Speed, Shift Formula
 * Tire Exchange: TBA
 * Type Used:
 * Type Speed, Type Formula
 * Bike Used:
 * Mach
 * Form Change: Mach
 * Signal Exchange: TBA
 * Form Used:
 * Mach
 * Chaser
 * Form Change: Chaser
 * Signal Exchange: TBA
 * Form Used:
 * Chaser