Himitsu no Himegimi Uwasa no Ouji
ひみつの姫君 うわさの王子
Two nations, Roochen and Galnia, have ended a prolonged conflict, requiring Princess Aldina of Roochen to wed the Galnian prince. Concerned by reports that the prince is a reckless and idle man, Aldina decides to investigate his true nature. To do so, she disguises herself as a boy and attempts to get close to him.