For the creamy ponzu dressing, blend all of the dressing ingredients, except the vegetable oil, to a smooth purée in a food processor.
With the motor still running, gradually pour in the vegetable oil in a thin stream, until the mixture has thickened and resembles mayonnaise. Season, to taste, with more yuzu juice, as required. Chill until needed.
For the squid, heat the oil in a deep fat fryer to 190C/374F. Alternatively, heat the oil in a deep heavy-based frying pan until a breadcrumb sizzles and turns brown when dropped into it. (CAUTION: hot oil can be dangerous. Do not leave unattended.)
Sprinkle the flour onto a plate and season, to taste, with salt and freshly ground black pepper.
Dredge the squid rings in the seasoned flour until completely coated, shaking off any excess.
Beat the eggs in a bowl, then sprinkle the Japanese panko breadcrumbs onto a separate plate.
Dip each floured squid ring first in the beaten egg, then dredge it in the panko breadcrumbs until completely coated.
Carefully lower the coated squid rings, in batches, into the hot oil. Fry for 2-3 minutes, or until crisp and golden-brown. Remove from the oil using a slotted spoon and set aside to drain on kitchen paper. Keep warm. Repeat the process with the remaining coated squid rings.
To serve, divide the crispy breadcrumbed squid equally among four serving plates. Drizzle over the creamy ponzu dressing. Serve immediately.