Aina

Aina is one of the main female characters in the manga and light novel "I Have a Slow Living in Different World (I Wish)." She and Sorte are knights from Red Front, which is a group part of the Adventurer's Guild. After fellow members of the adventurer's guild destroyed the potions Itsuki made, Reinrich (who is Itsuki's master and is very famous in the city) asked for a compensation (a very expensive one) otherwise the Alchemy Guild would stop cooperating with the Adventurer's Guild. Aina, despite not being the one who destroyed the potions, offered to become his slave as a compensation. Itsuki was moved by her kindness and declined but Reinrich acknowledged the idea, therefore she became her slave.