Aya loves her childhood friend Yuna, but Yuna is good at everything and Aya worries that she's not good enough for her. The metaphor of Earth and Mars is used to describe their relationship/situation. Aya loves her childhood friend Yuna, but Yuna is good at everything and Aya worries that she's not good enough for her. The metaphor of Earth and Mars is used to describe their relationship/situation. Show less