Shinigami ni Sodaterareta Shoujo wa Shikkoku no Ken wo Mune ni Idaku

This is a manga about a cute girl doing not-so-cute things cutely. Specifically, it follows Olivia, an orphan adopted by Death (yes, the one with the scythe), taught to be a powerful fighter, and then let lose on the world. Olivia doesn't fully understand human social interactions, but she makes up for it with her childlike wonder and glee at mundane things... and by carrying out her soldier duties with the same childlike wonder and glee, which, while effective, is off-putting to many of her peers.

And... that's about it, for now. The story hints at larger plots in the form of an international war and the rationale for why Death saw fit to let Olivia back into the world of humans, but Olivia herself isn't actively pursuing any particular motive, nor did I connect strongly enough with the other characters to really care about their perspectives. The humor is nice when Olivia's Slice of Life gets mixed up with her Life of Slicing, but if you're looking for more than that, I've had trouble finding it. Perhaps later volumes will change this.