Rinse each rib under cold water to wash off any bone dust from the saw. Lay them out on paper towels and dry them very well.
Combine soy sauce, salt, brown sugar, mirin, sesame oil, pear, kiwi, onion, garlic, ginger, and black pepper in a blender. Blend until completely smooth.
Lay all the ribs in 2 layers in a 9x13 baking dish. Pour the blended marinade over them and brush every piece so it's heavily coated on both sides. Cover with a lid (plastic wrap works too) and refrigerate overnight (12-18 hours is ideal).
Preheat Grill on high to 450-500°F (260°C)
Spray or wipe the grates liberally with oil, then lay each rib on the grill, letting the excess marinade drip off first. Close the lid and sear 3-4 minutes. Reserve the excess marinade.
Flip each rib, brush the top sides with marinade, then close the lid again. Reduce grill heat to medium and cook for 1-2 minutes. Open the lid, flip the ribs, brush with more marinade, close the lid and reduce heat to medium. Open, flip, brush, and close a second maneuver 2 more times. Don't brush with marinade on the last flip (you'll likely be out of marinade at this point anyway). The total cook time for ribs should be 10-12 minutes: 5-6 minutes over medium high heat, 5-6 minutes over medium.
Transfer the ribs to a plate and rest for 5 minutes. They're thin, so they don't need long.
To serve cut into bite sized pieces with scissors between the bones