Unknown Koroshiya-san So Cute

It's been a month since 25-year-old Tsukushi Yoi was fired from her last job. In the midst of doubts about her future, she discovers a mysterious young person sitting right in front of her house. Are they a boy? A girl? They look like an angel, but turn out to be a professional killer of indeterminate gender...

It's under these strange circumstances that Tsukushi begins a strange life together with this far too cute killer, but will her heart be able to hold out?

(Source: Houbunsha, translated)

Note: Includes an extra chapter.