Explain sai fongs solution to Mario's problem with chester

Sai Fong invites them to eat. Mario tries all sorts of noodles, rice, vegetables, and even duck, learning how to use chopsticks in the process. Chester tastes everything, too, in a small saucer that Sai Fong puts out for him. After they finish eating, Mario explains that he is worried about Chester's diet. In response, Sai Fong and his friend pull out a big book and read through it until the find the story they were looking for, about a princess in ancient China who had a pet cricket and fed him mulberry leaves.

Luckily Sai Fong has a mulberry tree outside his window. They pick off a leaf and feed it to Chester, who likes it but is too full from dinner to eat much of it. He is extremely content, though, and begins to sing his cricket song, treating them all to a concert. The two Chinese men love it. It is late, though, so Mario decides to go back home, but Sai Fong tells him to come back any time to take more leaves for the cricket.