The Princess of Convenient Plot Devices, Vol. 6 (Manga) -

The chaos at the junior ball finally ends, and the next morning, Octavia finds herself back home in bed at the royal castle with the wound on her hand healing. But just when she thinks life will return to normal, the princess learns she's confined to her room under house arrest...and Klifford is in trouble for allowing her to get hurt?! To solve this mess, Octavia demands answers from her own brother, Sirius--the man pushing for Klifford's punishment!