KITA Naoe

One day, Watanabe Tsuna went to visit Katsuna hime-sama. To his horror, he chanced upon a man drinking blood from his beloved Katsuna hime-sama! In a fit of fury, he cut of the man's hand only to realize the man was none other than his childhood friend Ibaraki Douji! What is going on here? (from mangaupdates)

Long ago, the Emperor possessed great mystical powers... and now, a young boy wonders: will he have them as well. With no memories, and only a rose-shaped scar on his forehead as a clue, he ponders his legacy while on the run with the girl who rescued him from a group of armed warriors. She takes him to a scientist who seems sure Rose is the Emperor's clone, and that this young boy must assume the mantle of leadership. But opposing forces have created another clone from the Emperor's DNA... and the struggle for power begins. (from mangaupdates)

Yukito, who has inherited the blood of the king of Fantasia, is about to be taken away to the demon world by the wizard Bell. However, thanks to the cooperation of his older brother Kazuto and Akito, Bell ended up in this world. Yukito seems to have escaped danger, but monsters attack Yukito, aiming at the king's blood and the power of the king's beast that lives there!