Fate/Extra CCC Collaboration Event (US)/Free Quests/Front

Devil Elbow
Obtain  Gate Key (Elbow) to unlock.

Kind Thenar
Obtain  Gate Key (Kind) to unlock.

Landing Thigh
Clear Mission 33 : Defeat 30 Sakura Bots.

Ankle Link
Obtain  Gate Key (Ankle) to unlock.

Link Ankle
Clear Mission 35 : Defeat 30 Sakura Handlers.