I said I’d rather be here alone

When the older brother of Oikawa Tooru is killed in battle, the omega is set to be wedded off to keep the political stability of the Western kingdom. How will the Southern prince, Iwaizumi Hajime, treat his new partner? Will Tooru be able to capture the Southern subjects hearts and eventually be accepted as their new queen? And, will the two ever be able to see eye to eye within their arranged relationship? (I just copy pasted this draft from AO3 so the format might be weird+this is boys love/bl)