Citrus secret love affair with sister

"Yuzu and Mei may be step-sisters, but that's about all the two girls have in common. Yuzu is an outgoing girly-girl who cares more about fashion than school work, while Mei is the serious student council president. Yet despite their differences, or perhaps because of them, the two girls find themselves drawn to each other... Mei has been running herself ragged trying to oversee the school, and Yuzu is worried about her. When Mei's dad comes home from a business trip, however, it looks like the cavalry has arrived. Unfortunately, his presence opens up old wounds between father and daughter, and Yuzu finds herself caught in the middle. Will Yuzu put aside her feelings for Mei to help fix this family feud?" -- goodreads.com