I'm Fine With Being The Second Girlfriend

Shirou Kirishima and Akane Hayasaka share a secret relationship, keeping their connection hidden from everyone else. Though each of them has feelings for someone else, they act like lovers whenever they are alone, knowing all the while that their hearts ache for their first choices. They have even made a promise to end their arrangement the instant their feelings for those first choices become mutual. Yet as they grow closer to each other and to their respective crushes, the act they maintain begins to feel real—unexpectedly so. The careful distance they once relied on starts to blur, and the choice ahead becomes far more complicated than either anticipated. When they must decide between their crush and the person who has grown closest to them, will they be able to make the right choice?