Happy Kanako's Killer Life(2018)

Shiawase Kanako no Koroshiya Seikatsu

When Kanako accidentally applies to work at an assassination agency, the timid office worker discovers that she has a knack for bumping people off. Will she ever earn the respect of Sakurai, her prickly and kinda hot co-worker–and why is she still having silly workplace problems when she’s employed with hitmen?! This full-color manga is dangerously funny!

(Source: Seven Seas Entertainment)

Note: Originally a doujin, it was later serialized in twi4 on April 26, 2019 where the story continued.