Founded in 2019 by London-based sisters Kathryn and Millie Allsopp, Usisi Sister (pronounced oo-see-see) embodies sisterhood through fashion. The name means 'Sister' in Xhosa, reflecting their South African heritage through their mother who grew up in Cape Town. Despite a decade age gap, the sisters discovered they consistently purchased identical pieces in different colors, inspiring their concept of elevated wardrobe staples offered in just two colorways. Central to their philosophy are "suitcase capsules" - versatile collections designed to mix and match seamlessly for travel and everyday wear. Described by Women's Wear Daily as having "a foundation of sisterhood, empowering women and addressing climate change," the brand prioritizes circular fashion principles using sustainable materials like cupro and FSC-certified viscose. Available at leading retailers including Net-a-Porter and Farfetch, Usisi Sister has expanded from essentials to sustainable swimwear, maintaining a commitment to timeless design with a modern, feminine aesthetic that celebrates the community derived from sisterhood.