Ouji to Kotori  

Prince and Small Bird, 王子と小鳥

Suzuki Keiichi is an art school student who wakes up in a desert land with no idea how he got there or why he's there. He discovers that he has been bought at auction to pay off his debts and is now serving as the prince's younger brother's servant. Despite trying to escape, Suzuki becomes increasingly captivated by the prince's charm. The story is from a manga called "Yamanaka Hikos hit tankoubon" and also includes an unrelated oneshot titled "Sabishisa no Nedan".