From Bakeneko Scanlations:
Nozomu has come as a chaperone for his younger sister to a foreign country named Alusamito, where she has to have a marriage interview with a prince, because Nozomu’s family’s economical situation is bad. It turns out that the marriage partner is Nozomi’s childhood friend, Laud, with which he used to play with. But Laud has changed from the nice boy he used to know, into a man who is arrogant and unlovable…!! Furthermore, Laud suggests to Nozomu, who is already worried about his sister becoming only one of Laud’s wives, that he should become his wife in place of his sister…!?
Let the romance in the desert palace begin to unfold!