I don't know if it's reassuring or not that Kodansha has always been peddling shojo manga about taming Asshole-kuns to Americans, even when they were Del Ray Manga.
FOUR-EYED PRINCE (Megane Oji), by Wataru Mizukami. First published in 2007 and first published in North America in 2009.
PLOT:
Sachiko thought it was bad enough when her confession to the stoic class prince Akihiro was rejected. Then she had to move in with her long-absent mother after her grandmother had to go to a nursing home, and during that time her mother married Akihiro's father. Now her crush is her step-brother and the two of them have to find a way to live together harmoniously. That's no small challenge considering that Sachiko's crush is still going strong in spite of Akihiro's regular attempts to needle her, embarass her, and deny any connection to her as much as humanly possible.