Shikaku

"Shikaku is a young girl who has made a name for herself as a hitman."

After a childhood of abuse, Shikaku is now an infamous assassin. She gets hired by Yugeru, a 3,500-year-old vampire, to end his tiresome and boring life. However, not even Shikaku was able to fulfill his wish. Upon returning home, Shikaku finds herself unable to stop thinking about Yugeru as unfamiliar emotions torment her heart.