From Chibi Manga:
Even though I still haven’t experienced love yet, a political marriage!? Even though there’s someone I like, even though I’m still in high school… I have to marry someone I just met…!? The extremely poor high school girl Aoi is receiving help from the wealthy family Kirasagi. Despite her having feelings for her childhood friend and medical student Souta, Aoi knows the young lady Yukari of the Kirasagi household is in love with him. So she locks away her own feelings.

In the middle of this, the topic of Yukari’s political marriage to the young CEO Hagane Takatori is brought up. Aoi, who wishes to repay Yukari and her father’s kindness, becomes an adopted daughter of the Kirasagi’s and decides to marry Hagane…?

She is sweetly, fiercely loved by him…!? The beginning of an exciting love-square!