What is it about? I'm asking because I'm way too lazy to click on the video.
Cliff notes version of the set-up
> Evil spirits escape Hades (The Afterlife) and go back to the Living World to find suitable hosts to possess.
> Chloe Love is a 28 year old struggling actress (who looks younger than she is) who grew up in the slums, who it turns out is a very powerful spirit medium, making her a prime target for the evil spirits.
> Kai Iod is a spirit who is a member of Arkham Bullet (and a superfan of Chloe's), who basically wipe out evil spirits when they stir up trouble.
> Both of them essentially end up saving each other and it turns out Chloe can transform by having spirits possess her, gaining different abilities and attributes depending on the spirit.
> Chloe joins Arkham Bullet, becoming the titular Ghost Reaper Girl, both to make a better living doing something she's naturally talented at and obviously to become strong enough to protect herself and others from the evil spirits.
There's other stuff like an obvious Lovecraft influence (especially with the monster designs) with several characters being expys of Lovecraftian deities and even the principal antagonists are the "Great Old Ones".
I will warn you now that Kai is a self-professed lolicon. However this is pretty quickly shown as a character flaw (never seen as a good thing), the object of his affections is a 28 year old woman (he never shows interest in actual children), he's too obsessed with being a gentleman to do anything anyway and in general his character is interesting and likable enough regardless to make up for it IMO.
I can look passed it but I know it puts a lot of people off reading it entirely so it's up to you if you want to give it a shot.