Place 1 cup of tempura batter mix into a bowl and add 1/2 cup of water along with all of the spices listed above. Whisk everything together until thick or a pancake batter consistency.
Cut avocado's in half, then slice into half inch slices lengthwise.
Pour 2 cups of canola oil (or your oil of choice) into a frying pan and turn the heat to Medium (7). You can also use a deep fryer.
While waiting for the oil to heat up, Coat the avocado slices with the tempura batter. You may want to use two forks to toss them back and forth if you don't want to get too messy. But since avocados are quite fragile and slippery, the two-fork method is much more manageable and cleaner for me. Otherwise, you may also use your hands if you want :).
By this time, the oil should be hot enough to start frying the avocado's. Cooked when golden brown.
To make the teriyaki-lemon dipping sauce: combine 1/2 cup of kewpie japanese mayo (or light mayo if you don't have), 1/4 cup of kikkoman teryiaki sauce, and a squeeze of lemon juice. Adding wasabi is also optional for those who like it spicy. mix well.
When avocado's are cooked golden brown, place them on some paper towels to absorb excess oil. Feel free to double fry them for extra crunchiness!
Serve with teriyaki-lemon dipping sauce.