The two realms of yin and yang are not opposites, but connected by "obsession". The souls of the dead linger in the world because someone owed them something while they were still alive, or they owed something to someone else. One time while delivering food on a rainy night, an APP called "Huangquan Takeout" suddenly popped up on my phone. After receiving the order, the delivery is no longer a takeaway from the human world, but an order from the underworld - helping the dead souls fulfill their unfulfilled wishes. Every time you complete an order, you will receive "Yin Virtue Points", which can be exchanged for real rewards (cash, medical skills, treasure appraisal ability, etc.).
