Magical Otoge Ciel

Magical Otoge Ciel is a pure-hearted romance and comedy visual novel where you play as Ciel, a kind and ambitious princess who wants to finally go out on an adventure, set in a magical world.
Accompanying her are two knight brothers, Florien (the loyal, fluffy, and sarcastic childhood friend) and Anton (calm, cool, and serious stick-in-the-mud).

There's also a certain trickster and third wheel named Yvin who ends up following them around. He's not a thief, but he'll steal your heart in the most awkward way possible, hopefully.