A*D: Tenshi no Uso

The fourth son of the famous Caluanthes family is, well, quite infamous. Mockingly referred to as a bird of paradise, Fourth dresses gaudily, spends money like water, and has turned the trip he's been sent on to learn more about the world into his own personal gourmet dining tour. His behavior makes the rest of high society whisper about him behind his back. The only exception is Eiri Lawrence, who finds Fourth and his entourage intriguing rather than laughable, and who is everything that Fourth is not. Theirs is the world of high society, where truth and falsehood, and dark and light, intertwine.

(Source: Storm in Heaven Scanlations)