Ep 10. Episode 10

Shim Cheong is still struggling to adapt to life on land, but Joon Jae is doing his best to help her. They go shopping together for new clothes, and Joon Jae is amazed at how quickly Shim Cheong is able to pick up on the latest fashion trends. He is also struck by how innocent and pure she is, as she doesn't understand the implications of some of the things she says or does.

Meanwhile, Joon Jae's mother is still suspicious of Shim Cheong and her intentions. She decides to investigate Shim Cheong's past, and reaches out to a friend who happens to be a detective. The detective does a thorough background check on Shim Cheong, but can't find anything out of the ordinary. Joon Jae's mother is still not convinced, however, and continues to keep a close eye on Shim Cheong.

As Joon Jae and Shim Cheong continue to spend more time together, they grow closer and begin to develop deeper feelings for each other. Joon Jae is hesitant to act on his feelings, however, as he knows that Shim Cheong is not from this world and is unsure of what their future could hold.

One day, Joon Jae's ex-girlfriend shows up unexpectedly at his apartment. She tells Joon Jae that she still has feelings for him and wants to get back together. Joon Jae is torn between his feelings for Shim Cheong and his history with his ex-girlfriend, and he doesn't know what to do.

Meanwhile, a powerful new antagonist is introduced. He is a wealthy businessman who is secretly a merman, and he has had his eye on Shim Cheong for a long time. He sees her as a valuable asset and wants to take her captive in order to harness her powers for his own purposes. Shim Cheong is completely unaware of his intentions, and Joon Jae must do everything in his power to protect her from this dangerous newcomer.

As the episode ends, Joon Jae must make a decision about his relationship with Shim Cheong. He realizes that he cares deeply for her, but he is unsure if he can commit to her given the many challenges they would likely face in the future. Meanwhile, the businessman continues to plot his next move, and Shim Cheong remains in danger. The stage is set for an explosive confrontation that will have far-reaching consequences for all of the characters involved.