Peel the Sumo orange and separate the segments. Chop the segments into smaller pieces, reserving a few for garnish.
In a medium bowl, whisk together the milk, Greek yogurt, maple syrup, and a pinch of salt until smooth.
Add the chia seeds and whisk thoroughly to combine, ensuring no clumps.
Gently fold in the chopped Sumo orange segments.
Cover the bowl and refrigerate overnight, allowing the chia seeds to absorb the liquid and create a pudding-like consistency.
Once set, stir the pudding and divide it between serving glasses or bowls.
Garnish with the reserved Sumo orange segments and additional garnishes if desired. Serve chilled and enjoy!