A new and distinct cultivar of Osteospermum plant named \u2018Duetisushine\u2019, characterized by its compact, upright and mounded plant habit; freely branching growth habit; freely flowering habit; and daisy-type inflorescences with elongated oblong-shaped ray florets that are clear yellow in color. The platform is positioned to allow easy access. A sealing member is positioned in the first expanded region, a retainer is positioned in the second expanded region and a support washer having transversely oriented radial and coaxial flanges is positioned adjacent to the retainer.