Unmei wa Suki wo Akiramenai!

A relationship that can't end...what should I do with this feeling? Tenma, a unicorn, has had feelings for Irima, an incubus who has been his best friend since he was little. However, unicorns, who must be bound to a virgin for the rest of their lives, cannot partner with an incubus who desires semen.... He is always worried about whether or not Irima will have sex with someone else. For those who are worried about having sex with someone else, Tenma has a “practice” routine. Tenma says it's “practice” and when he's in heat, the two of them do naughty things together...