He Rong, who was originally the first fish in the fish tank, failed to become that fish because of the amniotic fluid in her belly. Instead, she gained a sister who loved her and met a person.
She accidentally fell into the fish tank and became He Yi. He Yong fed her, gave her "love", and changed the water in the fish tank for her. In the end, He Yi became the drowned fish.
Many years later, He Rong met He Yi's former friend...
Purpose: Female growth