As the sun sets, a boy plays fetch/catch with his happy little Mawisha on the riverbank. [Insert interminable scene of Mawisha and the boy playing.] After a while, Mawisha wants to go home and eat, but the boy wants to stay--he wishes they could play there forever. He throws the ball extra-hard, and as Mawisha runs off after it, he walks back to his mother waiting on the embankment above.
Although Mawisha remembered that the riverbank is where the boy met her and said he'd make her his pet, she doesn't remember that it happened that same day, and just a short time earlier, she was crying and cursing as he brought her back. Feeling sad about losing his "pet" and feeling guilty about dashing Mawisha's hopes, the boy hopes that she forgets all about him soon. His mother gently reminds him that when people adopt yukkuris that haven't been trained by the Factory or a pet shop, both the people and the yukkuris end up unhappy--that's why people buy expensive yukkuris when they could have any number of strays for free. She says that when the boy is a little older, they can think about getting a proper pet yukkuri.
Still chasing the ball, Mawisha disappears into the tall grass. The boy and his mother walk home.