18+ Ore to Fuuki Iin no.

Up until two weeks ago, Riku Kurata has lived his entire life as a boy. However, his whole world changes when his father informs him of his plans to remarry. The woman his father intends to marry also has a son, and having two sons in the family will create inheritance issues down the line. To avoid further conflicts, Riku's father lies about having a daughter, and Riku must now shoulder this facade until he completes his compulsory education and leaves his home.

Though annoyed by the situation, Riku does not pay much mind to it until he is partnered up with Shunichi Ozaki, a public morals committee member at the school he recently transferred to. Ozaki quickly points out that he is aware of Riku's secret but will keep his mouth shut as long as Riku does everything he says. Not wanting to be exposed for crossdressing, Riku reluctantly agrees yet quickly finds himself in increasingly uncomfortable situations with his classmate.