Elle has always believed that hard work was her way forward. Freshly graduated from college, she returns home with plans to leave again soon, hoping to build the life she has carefully imagined. Home is meant to be temporary, but it quickly becomes unfamiliar. Her mother Annette is struggling with her mental health in ways Elle cannot fully understand, and the stability of their household begins to quietly erode.

When Annette disappears, the fragile balance holding the family together collapses. With no clear answers and little support, Elle becomes responsible for her younger sister Cassidy. The future Elle planned, including her dreams of leaving home, begins to feel increasingly distant as the demands of care and survival take over her days.

As the sisters navigate life on their own, grief settles unevenly between them. Elle carries the weight of responsibility while mourning both her mother and the life she thought she was moving toward. Cassidy, still caught between childhood and awareness, looks to her sister for reassurance even as both struggle to adapt to their new reality. Their bond is tested by exhaustion, resentment, and a love that endures even when it feels heavy.

Betta Fish is an intimate portrait of sisterhood, resilience, and the quiet ways grief, love, and responsibility can reshape a life.