To Your Eternity features a character whose past involves a desire to change gender. Pioran, an elderly woman, is revealed to have been a man who wished to become a woman for love. This aspect of her identity is depicted with dignity and complexity, integrated respectfully into her character's arc. The narrative treats her journey with empathy, affirming her life and choices.

The series features Tonari, a young leader who actively participates in combat. She is shown using a whip to effectively engage and overcome multiple adult male opponents in close-quarters fights during the Jananda Island arc. These instances demonstrate her skill and capability in direct physical confrontations.

The narrative of To Your Eternity consistently celebrates alternative family structures, prioritizing bonds formed through shared experience and empathy over traditional biological ties. It explores the fluidity of roles within these non-conventional units, highlighting the importance of chosen family.