The Kimewaza Slot Holder (キメワザスロットホルダー,Kimewaza Surotto Horudā, lit. "Finisher Technique Slot Holder") is a Rider Gashat holder and has special slot to activate a Rider Gashat's Critical Strike finisher. This slot is attached on the left side of the Gamer Driver.
When the Holder Switch is pushed without any Gashat in the Kimewaza Slot, "STAGE Select" (ステージセレクト,Sutēji Serekuto) is activated.
When the active Mighty Action X Gashat is removed from the Gamer Driver and inserted to the Kimewaza Slot, with the Holder Switch pushed, energy will be gathered at the Rider's right leg, and when the Switch is pushed again, the "Mighty Critical Strike" finisher will be performed.