Hana is a Grim Reaper, who guides the souls of the deceased to the right path.
Due to her clumsy personality and unlucky nature, everything she did usually ended up in disaster. Hana didn't have much luck in life as well. It was safe to say everything she did proactively would end up in failure. Because of this, Hana is still afraid to act even as an employee of After World Inc.
Hana works hard as a Grim Reaper, but thanks to her mistakes she's not coming up with results. Her mistakes and bad luck mount up to making the matters worse instead. Her performance review is rock bottom and Hana's been branded as a useless Grim Reaper in the company.
When Hana was alive, people around her would suddenly end up dead to the point of arousing suspicion. Some just considered it as superstition, but those who became close to Hana all ended up dying after a while. As these incidents continued, the villagers left Hana one by one, and soon Hana was all alone. This left a deep mark within Hana's soul, and she started getting scared of becoming closer to other spirits.
Spirits who leave strong resentment and regret in life lose all of their memories when coming to the After World. The spirits who lost their memories end up wandering the nether or become Grim Reapers in the After World.
Through some event, some Grim Reapers regain their memories and solve their resentments and regrets, but these cases are very rare. Most end up working for eternity. Through this process, Grim Reapers are growing in numbers, but because the population is growing faster, After World Inc is constantly needing more manpower.