Ouji no Torimaki A wa Akuyaku Reijou no Mikata desu

From Google Translate:

The first prince is head over heels in love with the pretty daughter of a baron. One day, Roland, known as "The Prince's Henchman A," who is good at flattering others, notices an abnormal situation in which all of the henchman's entourage, including the prince, are obsessed with one young lady. In order to save the villainous young lady, who is the prince's fiancée, from the verge of being unfairly called off, he secretly works behind the scenes.