Peel and devein the shrimp, leaving the tails on
Make shallow slits on the underside of each shrimp and gently press to straighten
Pat the shrimp dry
Chill the shrimp in the refrigerator
Prepare the tempura batter with ice-cold water, flour, and egg
Mix the batter lightly until just combined
Heat oil in a deep pan to about 350°F to 375°F
Lightly dust the shrimp with flour
Dip each shrimp into the tempura batter
Carefully place the shrimp into the hot oil
Fry until light golden and crisp
Remove and drain on a wire rack or paper towels
Serve immediately with tempura dipping sauce