Koi Yori Kiss Yori Daikirai

Nakanomori Yuzu’s family used to run a dojo. But when the Tenmonzaki family opens a rival business next door, they went bankrupt in a blink of an eye. Her parents died in a car crash shortly afterwards, leaving Yuzu and her brother in poverty, struggling to pay off their debts. Yuzu, in search for revenge against the Tenmozaki family, swears to defeat their son around her age: the rich and talented Tenmonzaki Yuu. She enters the elite National Tamateba High School in order to fulfill her goal, but finds that first impressions are not all what they seem- especially concerning Yuu.
From NOIR:
Our poor female character is a poor girl with a debt to the rich and powerful Tenmonchiki. She accepts to be a slave in order to pay off her debts but what are these feelings starting to bloom within her heart…? Could she possibly love this rich, arrogant and all too perfect guy?