Since we don't have the full story, it's hard to say exactly who Suzy Perez is. She might be a character that represents a certain group of people. For example, if the story is about immigrants, she could be an immigrant herself, facing the typical challenges and joys that come with starting a new life in a different place. Or if it's a story set in a school, she could be a student, a teacher, or someone related to the school in a unique way.
One idea could be a rengoku fanfic where he trains a new group of young slayers. It could focus on his unique teaching methods and how he instills his values in them.
Tanjiro would be a great character to pair with rengoku. Their different personalities could create an interesting interaction. Tanjiro's kind - hearted nature and rengoku's fiery determination could lead to some great storylines.
I'm sorry, I don't know the specific 'Suzy Perez story'. Maybe she is a unique individual with her own personal experiences, dreams, and adventures that only those close to her or in her community might be fully aware of.