**Xiaoyu Lei** Nineteen-year-old bodyguard Xiaoyu Lei serves the Shinoyama Clan, assigned to protect Sayo Shinoyama during her stay with an individual impersonating her half-uncle, Polka Shinoyama. Originating from the Lei Family assassin guild Heilei, his youthful appearance belies significant cybernetic enhancements: prosthetic legs, a synthetic left arm mimicking organic function, and a right arm replaced by the limb of Urdwigia, a mythical lightning dragon. Artificial fingers serve as combat extensions. An internal high-sensitivity microphone enables eavesdropping on distant conversations. **Background** Born into Heilei, Xiaoyu trained as an assassin from early childhood. Around age nine or ten, his first mission—to eliminate terrorists threatening the Lei Family—ended when he found the targets already dead by Majiri, Kana, and Momoya Agakura. Attempting to slit Majiri’s throat, Xiaoyu had his limbs non-lethally severed. Majiri offered to return them if he joined the Agakura Clan. Hospitalized limbless, he overheard his father planning to use him as a "t'ing-fu" (a living host for cultivating poisonous bacteria). Rozan Shinoyama intervened, purchasing Xiaoyu to test experimental cybernetic prosthetics. This act forged Xiaoyu’s fanatical loyalty to Rozan, who expressed hope Xiaoyu would become a companion to the Shinoyama family. Xiaoyu resented Rozan’s biological son, Polka Shinoyama, perceiving him as weak and undeserving of Rozan’s affection. This jealousy evolved into a superiority complex; Xiaoyu believed himself the more capable and devoted "son" worthy of replacing Polka. His resentment persisted even after Polka fled the Shinoyama estate. **Present Role and Actions** After Corpse God reincarnated into Polka’s body, Rozan tasked Xiaoyu with protecting Sayo and the impostor at Polka’s Shinjuku residence. Xiaoyu outwardly accepted but privately vowed to eliminate both the impostor and Polka if alive, justifying this as protecting the Shinoyamas. During the assignment, Xiaoyu eavesdropped on Corpse God’s conversations, suspecting hidden agendas. He tracked detectives Iwanome and Arase after Corpse God’s fortunetelling provoked an unusual reaction from Iwanome, leading Xiaoyu to investigate connections involving Miyabi Hosorogi—a spirit linked to Misaki Sakimiya’s possessions. Xiaoyu later confronted Momoya Agakura at a hideout where Takumi Kuruya was being tortured. When Momoya nearly killed him in combat, the Vampire Larva Misaki intervened. Xiaoyu retaliated by piercing Momoya’s body with his prosthetic fingers, critically injuring him. **Personality and Motivations** Xiaoyu projects capability and eagerness to please while harboring intense suspicion and murderous intent. He distrusts Corpse God despite Rozan’s explicit trust, driven by jealousy and a compulsive need to prove himself Rozan’s ideal protector and "son." His extreme stubbornness manifests in late-night surveillance and covert operations, sometimes to comical extremes. Pride enables him to openly defy his biological family, the Heilei, reaffirming loyalty to the Shinoyamas. **Key Relationships** - **Rozan Shinoyama:** Credits Rozan with saving him; views him as a father figure. Seeks Rozan’s approval above all. - **Polka Shinoyama:** Primary target of resentment as an unworthy rival for Rozan’s affection. - **Sayo Shinoyama:** Protected dutifully, though his assignment serves as a pretext to monitor Corpse God. - **Momoya Agakura:** Adversarial history began during Xiaoyu’s first mission; their clash resulted in mutual severe injury.