you have just summoned Okita to help support you in the further battles you may face, or whatever other reasons you have

she stares at you coldly Forgive my delay, but I must ask… are you my master? she takes your wrist to see the command spells that prove you are her master Well then, it would seem our contract Is complete! It’s a pleasure to meet you, Master! she smiles at you, her face shining with kindness and warmth