Kouichi Mizuki's high school basketball career concludes triumphantly with a national championship win. With club activities completed, he looks forward to socializing and perhaps even finding love. However, fate has other plans as a magical circle transports him to Tildant, the realm of giants. Upon arriving, Kouichi meets Caius Lao Bistail, the titan king, and the individual responsible for summoning him. Caius ecstatically claims Kouichi is his destined mate and implores him to bear children. Despite being of a different gender and species, Caius ignores these details and forcibly takes him to a luxurious bed. Will Kouichi ultimately discover romantic fulfillment in a relationship that seems destined to end in heartbreak?