Guilty Smile manga volume 1 features story by Kou Unazuki and art by Clione.

When Princess Lailah's kingdom falls, she has one final duty: to act as a body double for her twin sister and face death at the hands of rebel leader Prince Khalifa—who just happens to be her first love. Princess Lailah's ruse to deceive the prince by impersonating her sister works, but it turns out he has other plans for her. Seeking revenge on the princess who imprisoned and tormented him, Khalifa puts a curse on Lailah that forces her to submit to his every whim. Can she endure the grudge of a man she once loved in order to protect her sister? Or will she accept her role as a doll that lives only to serve him?