The God of the underworld studied medicine and became the god of medicine. An accident allows an out of luck loser to prosper. By clinging to the god of the underworld, (hugging someone’s thigh means to sort of take advantage of their skills, knowledge, position, and learn from them too, like being carried in a game), studying under the famous doctor of ancient times, he acquires the skill of medicine and becomes the era’s medicine god. With girls on both arms, he’ll live the life of a harem master