It does. It was in the contract you clearly don't remember signing upon arrival.

[ Poor Espio... she knows what it's like, at least, to be alone. Before she'd met Ren and the others at home, that had been her existence for the most part. She'd only had one other person on her side for years... and she's not about to let Espio go without a friend or ally, because she knows what that's like. Especially in a place like that. ]

Sorry, Espio-san, but you're stuck in this friendship now~.