Wipe off excess oil from aburaage using a paper towel, then cut each piece in half horizontally.

Heat a pan with the seasoning mixture (sake, mirin, sugar, soy sauce, and water). Once boiling, add the aburaage, cover with a drop lid, and simmer on low heat for about 5 minutes. Let cool and squeeze out excess liquid.

Cut the unagi into bite-sized pieces, place them in a microwave-safe container, cover loosely with plastic wrap, and heat according to package instructions. Slice the shiso leaves and myoga thinly.

Boil somen noodles according to package instructions. Rinse under cold water, remove excess starch, and drain thoroughly. Mix the noodles with the simmered sauce, shiso leaves, and myoga in a bowl.