一家の経済的窮地のせいで妹が大富豪と見合いをすることになり、付き添いとして砂漠の王国・アルサーミーにやってきた希。見合い相手のラウド王子は、希の幼い頃の遊び友達だ。ところが、優しかったラウドは傲慢でいけ好かない男に変貌していた…!!　さらに一夫多妻制のことで妹を心配する希にラウドが提案してきたのは、『妹の代わりに妻になること』で──!?　熱砂の王宮で紡がれる問答無用の求愛ロマンスｖ

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!