Arata Funamori is an average middle-school boy, generally going about his life until meeting Chris Northfield, a transfer student. He and Chris become fast friends, and he is swiftly pulled into the young man's problems. Chris is the prince of a different world, Eldhiland, transported to this one as part of the Princess Waltz, a competition to choose his bride. Chris and Arata are able to fuse themselves into Iris, taking the place of the princess of Soldia. After finding out that Chris is actually a girl - and falling in love- he then finds out that Chris Northfield is actually an impostor, switched out at birth and manipulated to release the demon residing within the royal bloodline.
Chris herself is manipulated by this demon, known as Shichiou, into dying, allowing for his resurrection. Arata then finds out that he himself is the real Chris Northfield, and was switched out for his half-sibling and cousin at birth. Chris is possessed by Shichiou, a demon who is also the first king of Eldhiland. He then teams up with the other Princesses to rescue Chris, defeating Shichiou in the process. He takes his rightful throne, marrying Chris as his empress.
Fate/Shipping Wars (by Leolab)
Combatants: Arata Fukamori & Chris Northfield, Velvet Crowe & Eleanor Hume, Adam and Eve, Wes and Rui, Sypha Belnades (Netflix) & Trevor Belmont (Netflix), Arcueid Brunestud & Shiki Tohno, Ellen Kohagura & Kaoru Mashiko