In the prequel, The Hippocratic Crush I, Yat Kin (Kenneth Ma) and Yue Jai (Tavia Yeung) wrote letters to each other everyday. In the sequel, The Hippocratic Crush II, Yat Kin and Yue Jai challenge each other to figure out the combination of the number lock of a locker. Yue Jai hopes that through this experience, Yat Kin will learn how to relax.
For this number combination, Yue Jai sets a challenge for Yat Kin to use a wheelchair, to be able to understand how she will eventually have to be. Yat Kin does so and realizes that his wife is stronger than he thinks. These are from Episode 21.
Yue Jai tells him that she only wanted him to learn to relax and love himself more through these challenges. She asks him to come back home so they can make another hand sculpture, one of a pinky promise, together.