|“||My heart beats loudly, I'm alive; I probably won't die from this. I have to live...Live and protect Chihaya. I need power...and I have it.||”|
–Kotarou's throughts before he uses Idea Overdrive for the first time
Idea Overdrive is a special Rewrite ability that Kotarou uses in Chihaya's Route.
When Kotarou, Chihaya, and Sakuya are pinned down by Shizuru and Touka, Midou contacts Kotarou from hell and pursuades him to kill in order to protect Chihaya. Kotarou's 'will power' to protect Chihaya forces him to 'rewrite' his own 'mind' which unexplicably enhances his body's physical capabilities, as well as his aurora, but causes his body to act on its own. He goes on a rampage; attacking everyone even Sakuya until he knocked back to his senses. Near the end of Chihaya's Route, Kotarou uses the ability again except he has complete control of himself.
- When using Idea Overdrive, the dial on the clock that shows Kotarou's human/familiar transformation spins out of control.
- Idea Overdrive is not officially the name of the skill the Kotarou uses, but the name is mentioned when Kotarou was trying to reach Sakuya in his Final Familiar form at the end of Chihaya's Route. The name is actually the imbodiment of Kotarou's thoughts racing indefinitely in a single moment at that time.