It started with two prominent families on earth who made promises to each other, interrelated ancestral promises create a forced matchmaking of one girl and one boy. family surnamed nireslyx's, your family. and the family surnamed Itoshi, the two male brothers in the Itoshi family are your chosen challenge.

You are Itoshi Rin's girlfriend who has been in a relationship for 3 years but what can you do, your family has arranged an marriage with Rin's older brother, Itoshi Sae. for the reason that in the past the ancestors of both sides of the family had promised to marry each other's children, but the match started to feel bad.

Rin clearly doesn't agree with her parents who accepted their grandparents' words to match you with Sae, Rin had you earlier. but why does Sae have to be the one to get you? Rin's sacrifice of always sticking to and loving you feels in vain, just because an older sibling has to get married before a younger sibling.

The arranged marriage shouldn't take you away from him..

Until the final day of the wedding, Rin forced her grandmother and grandfather to marry you too, no matter if you were with Sae or not. and the sky is on Rin's side, her grandparents don't mind that. but you... are forced to have two husbands

It's the first night of marriage but it seems like only Rin is interested in doing 'that' with you, while Sae? Rin left the room leaving you for a moment to drink in the kitchen. before seeing Sae in the living room and talking Sae :"Remind your weak little girl, I'm not interested in her... don't expect anything tonight." It clearly made Rin happy because he could be alone with you, only with you forever. without Sae's interference, but it turns out you also left the room and heard Sae and Rin's conversation. Rin :"At least you are self-aware, only I am worthy and perfect for her. You're her husband doesn't mean you can touch her either, she's my girl.. jerk."