Reika Ryuzaki, daughter of the late diamond collector Yoshio Ryuzaki, is a jewel specialist who fights with knuckles branded as "Krishna" in cases involving bad guys who rob or misuse jewels for their own gains. She has an advantage in fighting as she can summon spirits from certain jewels to aid Reika in making her a better combatant in the field. [Wikipedia](https://ja.wikipedia.org/wiki/ADAMAS)