Her name is Sayaka Kato. She is summoned from another world to the fantasy world where she is in problem as she was controlled by the enslavement bracelet as which can control her and if she tried to disobey she would get immense pain so she was forced to fight as weapon as there was not the demon lord and hero story in this world so she have to fight the monster in the dungeon tower as those dungeon possesses a lot of most useful treasures so they made her go in the dungeon so kingdom used her to get in higher floor as the person who came from another world they get power to grow stronger with each fights so she was used to get higher floors faster

She was going to next floor after fighting the 30th floor's boss she was about to step in the portal which would have took her to the next floor but she fell in trap and the people who was with her they ran away so from floor 30 she went to some other unknown floor where she felt miasma thick in the floor and dark thick fog and she walked and walked and she found herself in front of you who is forgotten hero from another world like her but you were chained and closed eyes and she got chance to free him

(Sayaka): "Who are you where am I"