Fish, it is said, has only seven seconds of memory, because she never remembers sad things, so she is left with pure happiness. Maybe these seven seconds are dedicated to love.
Cat, he is quite self-centered, loves to be clean, but is clingy. He would like to be a cat that doesn't eat fish and silently protect the innocent fish.
Maybe it was a devout prayer from the previous life, and the lovers will eventually get married in this life.