I Heard I Have an Ocean to Inherit

Tang Wan has known since childhood that she is different, because she can breathe underwater as freely as a fish. After graduating from university, she opens a seaside guesthouse. She runs the guesthouse, leases a stretch of sea for aquaculture, and does a bit of livestreaming on the side. Her business takes off. Just as her livestreams go viral and she's about to reach the pinnacle of success, a police officer comes looking for her. Police officer: You're suspected of illegal business operations. Come with us. Tang Wan turns to her employees, gritting her teeth. "Don't let me find out which little bastard gave us away!" As humanity's destruction of the ocean grows ever more severe, marine ecosystems suffer devastating damage. A group of deep-sea natives are left with nowhere to retreat and have no choice but to find a way to save themselves. They decide to send an ancient tortoise, a thousand years old and now able to take human form at will, ashore to find the daughter born to the Demon King and a human more than twenty years ago. They hope she can help them survive. The Shanhai Guesthouse suddenly gets a few strange new employees. Every one of them is a glutton, eating as much in a single meal as an ordinary person does in a month. With her savings balance dwindling dangerously, Tang Wan has no choice but to come up with a way to make money fast. Thesis: Protecting the environment is everyone's responsibility