By filling up the third Gem’s gauge and activating its ability, you may capture the Tsukumogami you are facing.
There are nearly a hundred different Tsukumogami in the game.
A captured Tsukumogami acquires experience points after defeating an enemy, and
you'll become able to use the skills that they possess.
There are over a hundred skills for the player to acquire, including
attack, support and recovery type skills.
From a certain point, you'll be allowed to strengthen the Gems to enrich
your experience.
You can boost the Gems' fill rate in combat, or add special abilities to the
Gems.
You are able to keep a maximum of five captured Tsukumogami.
If you acquire a sixth one, the first one you captured will disappear.
You can enjoy special bonuses upon satisfying certain requirements, such as
arranging the five Tsukumogami in a certain order or capturing Tsukumogami of
the same type.