I Become Their Lover to Help Save the World?!

Year 2071, when the world's population was in decline for more than fifty years. The government has since made efforts to raise people's sexual desires while protecting the most important part of reproduction, women. Orange was raised by her grandparents after her parents passed away and despite the laws regarding the efforts connected nto human reproduction, she was thought of old beliefs like monogamy and the old etiquettes of sex and the idea of love. Love which has probably been forgotten as it complicates the law. How can she deal with the current system? And how can she handle two gorgeous man who wants her to take them as her husbands?