The I Doesn't Stop/That Guy's Name Is Accel (Ｉが止まらない／奴の名はアクセル Ai ga Tomaranai/Yatsu no Na wa Akuseru) is the ninteenth episode of Kamen Rider W. It is the first part of the 'I' arc, I standing for IceAge (Dopant), Investigation and Intensity. Following his cameos holding the Accel Memory at the end of Movie War 2010 and the previous episode, this episode introduces Ryu Terui, marking the debut of his Kamen Rider Accel transformation.