From Renta!

The kind, smitten Chiaki and the scary yet reliable Kazuma are a long-term gay couple. Tomoe, the tomboy who knows of their relationship, asks to see them, and they find her with a large tummy and another life growing inside her. The father is unknown, and although Chiaki and Kazuma are exasperated with the chipper Tomoe, they help her out. Before they know it, the baby is born. The two men are relieved that Tomoe is acting like a proper mother, but one day, Tomoe comes to them with tears in her eyes and says, "Take care of her for me...!" The bubbling motherly instincts, the increasing motherly skills, and the interrupted sex!?