This comic is based on a comment

HeraldOfPersona                                                                                  ∙ Shared September 12, 2022 at 7:18 PM

Basically, the reason why Grim says "You're hired" to Mika is that Grim thinks of Mika when she's in her Grim Reaper costume, as another fellow Grim Harvester and decides to hire her to help her alongside harvesting and leading souls to the afterlife.

HeraldOfPersona                                                                                  ∙ Shared September 12, 2022 at 7:19 PM

Not sure how Mika would think about harvesting and leading souls into the afterlife (as Grim Harvesters are said to be physical forms of spirits who have to finish a job, and Mika's not a spirit or even dead), but there's the context for Grim's lines.

BerriesNCream                     ∙ Shared September 12, 2022 at 7:27 PM

She only is dress like that bcuz She thinks Grim is neat XD