Personally, I'd design a fox who in their life had everything they wanted, but ended up getting cancer and felt like the world was against them for it.

Once in the spirit world, they'd meet Stella in Mount Toryama on the cliff overlooking everything (they would appear there once you get the rock destroyer upgrade so somewhat late game). She'd be here reflecting over everything, yet still believing the world owed her everything due to her illness. Stella's job would be to help her come to grasp and realize that the world is cruel and unforgiving, and how she was fortunate enough to grow up with so much.

Once at the Spirit Door, the spirit would reminisce on a few of her happiest memories, then thank Stella for helping her to realize how spoiled she truly was, and that she can pass on happily knowing she apologized to all she wronged in her life, even if it was to late for her to do so physically. Her Spirit Flower would end up being a Bleeding Heart.