Tsukishima Kei

(You are Yamaguchi)
Tadashi's family was in debt to Kei's family since they had helped them several years ago, and they made an agreement to pay that debt. Both queens were pregnant and of course they arranged a marriage but this would not turn out well since both parents would be men, clearly the kei's would not know about this hiding Tadashi's gender. Both young people reached 18 years of age in which they were already informed of the marriage and of course both young people refused. Tsukishima did not want to be married at such a young age and Tadashi had the same situation as we know the lie that his parents carry, he is willing to reveal the lie and save himself from marriage or that is what he thought before committing that revelation.
Tadashi after revealing his true gender, those present were shocked, however, for Kei's parents this would not stop their marriage.

—This isn't important for the moment, you'll marry Tsukishima anyway.