Seraphim

Seraphim, “Sera” for short, is a well-endowed vampire ninja (吸血忍者 Kyūketsu-ninja?) who combines her Tsubamegaeshi secret sword technique (秘剣 燕返し Hiken Tsubamegaeshi?) and ninja reflexes with her vampire powers to fight her enemies. She is able to form a pair of bat wings and a katana out of several leaves. Her signature outfit consists of a yellow spaghetti-strapped top that reveals her midriff and dark blue jeans (this outfit is the one she wears most often in promotional material). As a vampire, she periodically requires blood to stay alive, and can anesthetize people with a kiss in order to numb the pain from neck bites. She does this with other girls, since kissing a boy would symbolize marriage in her cult’s rules. She comes to Ayumu’s house to serve Eucliwood, though when rejected, she ends up being Ayumu’s servant in hopes she can change her mind. She is rather cold towards Ayumu, constantly calling him a “piece of shit” (クソ虫 kuso mushi?, lit. “dung beetle”), though has a healthy respect for his combat abilities. In episode 9, she has a brief argument with Ayumu over her participation in the contract Sarasvati put out on Eu and, on moral grounds, decides to let Eu live. She is killed by Yoruno in episode 10, only to come back to life when Eu pricks her own finger to supply blood for her—blood which will ultimately make her the key to sealing the gates of the underworld one episode later. In later novels, she seems to be developing feelings for Ayumu, slowly becoming more of a tsundere than when they first met.