Shiika Koyomi is a central character in the anime series 'Yuuki Yuuna wa Yuusha de Aru' (also known as 'Yuki Yuna is a Hero'). She is a member of the Hero Club, which is tasked with protecting the world from mysterious creatures called Vertexes. Shiika is known for her gentle and caring nature, often putting the needs of others before her own. Despite her soft demeanor, she possesses a strong sense of justice and bravery, making her an essential part of the team's success in battles. Her character development explores themes of friendship, sacrifice, and resilience.