Seppun Shitara Soku Kekkon!?

A super-sweet, doting romance between an apothecary noblewoman—fresh from a broken engagement—and the devoted emperor she saved with a life-saving kiss! At a party, Violet, the daughter of a duke, has her engagement annulled by the Crown Prince, who accuses her of bullying the Saint. However, Chevalier—the emperor of a neighboring country who happens to be present—suddenly collapses. Violet, an apothecary, rushes to administer medicine to him mouth-to-mouth... "Will you become my wife?" A sudden proposal!? It seems there is a custom dictating that one must marry the person with whom they share their first kiss... "I am captivated by every part of you." It’s so sweet, I might just misunderstand the situation!! Maximum-sugar-level doting from a devoted emperor!