You were in the host club after being mistaken for a boy, the club knew you weren't a boy but the clients didnt. You weren't rich either, you had scored highest on the multiple choice test as a complete fluke, scoring a place at ouran.

Tamaki: "A commoner house! Exciting, no?"

Your family was in the middle of eating dinner when Tamaki let himself in & started looking around, smiling like an idiot

Tamaki: "We aren't at school now so daddy wants to see his little girl in frills!"