The Princess of Convenient Plot Devices Novel Volume 4 was written by Mamecyoro with illustrations by Mitsuya Fuji.

The night of the junior ball ended with a well-earned victory, and the sun rose on a princess...under house-arrest?! Prince Sirius has Octavia on lockdown for endangering herself and Klifford detained on suspicions of orchestrating Sil’s carriage accident. It is Octavia’s turn to defend her guard, but can she prove his innocence in time? Danger is around the corner—the antiroyalists aren’t done with her yet!