Akane Suzumiya

As Haruka’s devoted younger sister, she initially views Takayuki and Mitsuki as surrogate siblings before discovering their secret romance. Her profound bond with Haruka is evident through her daily visits to her sister’s hospital bedside during her coma. Though a talented swimmer, she struggles with feelings of inadequacy compared to Mitsuki. This resentment deepens after a tragic accident, fueled by Mitsuki's perceived betrayal of both her talent and her sister, though she eventually overcomes this grief to become a premier Japanese swimmer.