Yoichi Saotome

Member of the Moon Demon Company, Shinoa Hiiragi Squad. Born on November 23. Sixteen years old. One of the test subjects of the "Seraph of the End." His demon weapon is the bow-shaped "Gekkouin."

He has a past where his older sister, Tomoe, was killed by vampires, which fueled his desire for revenge and led him to take the military enlistment exam, though he failed and continued his school life. However, after confronting vampires alongside Yuuichirou at school, they became friends and were both assigned to the Moon Demon Company.

He has a weak attachment to his own life, which allowed a demon to take over his body, but with the persuasion of Yuuichirou and Kimizuki, he managed to repel the control and succeeded in mastering it. Sayuri has praised him, saying, "His mental stability against demons is overwhelming," and he has also learned materialization on his own.

At Nagoya Airport, he witnessed the inhumane experiments of the Imperial Demon Army and defected from the military along with his squadmates. While acting together with them, he was approached by Ferid and others and went to Osaka, where he found Lax, his sister's killer. Enraged, he began to transform into a demon and was urged by Gekkouin to kill him, but he stopped the transformation by saying he would "kill him as painfully as possible." After returning to the Imperial Demon Army, he left the headquarters with Kimizuki, who was taking Mirai away due to the awakening of the First Progenitor. He heard from the demon-turned Guren that Tomoe's body was also being kept, which caused him to transform into a demon but was knocked unconscious. Later, he reunited with Shinoa and Mitsuba and headed to rescue Yuuichirou.