I remember a certain isekai manga with some details, but I forgot the title.

It is about a strong female MC who looks up to the male hero who rescued/saved her when she was a child. She vowed to be a very strong fighter and join the hero's party when she grows up. Years later, she became a very strong fighter/martial artist and joined the hero's party.

I am not sure that detail may be clear for me to remember but I think, in many situations, she pretends to be weak in front of the hero to get his attention.