Pat shrimp dry and place in a large bowl.
In a medium bowl combine garlic with ichimi togarashi, a little koshur salt and pepper and ponzu sauce. Stir in soysauce and cilantro. Taste and add more salt and pepper only if necessary.
Combine mixture with shrimp. Marinate 5 minutes or up to a few hours in the refrigerator. Thread shrimps from tail to head on bamboo skewers that have been soaked in cold water at least one hour. Grill shrimp on the barbecue, under the broiler or in a grill pan for 2 to 3 minutes on each side or until shrimps are opaque and cooked through.
Arrange shrimps on a platter and garnish with lemon slices.