The quote suggests that everyone carries their own inner struggles, represented as "fishes" in their stomach. Jiko, like everyone else, has these burdens. However, Haruki's challenge is far greater, symbolized by a massive whale, depicting a heavier emotional load. This imagery highlights the complexity of personal experiences, implying that some individuals bear weightier issues than others.
After becoming a nun, Jiko finds ways to connect with and release her burdens, enabling her to let the "whale" swim away. This transformation reflects the journey of opening oneself to emotional healing and the power of acceptance, suggesting that confronting and understanding one’s inner struggles can lead to liberation and peace.