Sumire Toyohara lives in a world where society is divided into three types: alpha, beta, and omega. Being an omega, Sumire had long seen and experienced the discrimination that comes with being one. But with the help of the newly passed Omega Employment Law, Sumire finally has the chance to work in the company of her dreams. However, she still has to hide her second nature to avoid biases. But things get complicated when Sumire goes into heat even though she'd taken her suppressants. Moreover, it's always around her colleague, Ryoji Tachibana, who always helped her through it. Could it be that 'destined mates' do exist in Sumire's case? (Source: Manga Planet)