かい
こころよ
None
The soul of a person has a hook that can make them pleasant. When you see, hear, or feel something pleasant, can't you feel that hook pressing into the middle of your body?
If you want to feel this pleasant feeling just look at a kayak (かい). Kayaks are the most pleasant boats in the world. Feel that pleasant feeling in your chest just from reading about kayaks in this mnemonic right now.