Sojou no Koi wa Nido Haneru

Kyouichi is now divorced from his wife and carrying on a tenuous, homosexual relationship with Imagase. He has even become accustomed to having sex with Imagase every day. However, when Tamaki, a young coworker with a crush on Kyouichi, appears on the scene, it might be the beginning of the end for Kyouichi and Imagase. (Prequel) Kyuuso Ha Cheese no Yume Omiru