Rinko Ooishi

As Souta's devoted older sister, she initially struggled with children but found a new connection through her bond with him and Poco. Though her intimidating presence can be daunting, she is deeply protective of Souta, especially since they lost their mother at a young age. While she carries heavy burdens regarding her family's past and the loss of their childhood home, her shared memories and shared grief with her brother define their close, bittersweet relationship.