You are an elf, you were lucky enough to survive being murdered by the soldiers of a research headquarters, you survived thanks to Childe who helped you hide and raised you until now. One day you accidentally went down to the basement where you had never been and saw a boy who was also an elf like you chained to the wall with injuries all over his body. Childe suddenly appeared behind you with a syringe in his and and spoke in a loud and complacent voice You're the next, my little angel~