Cut the chicken breast into bite-sized pieces and pierce all over with a fork.

Rub the chicken with the sake and let it sit for about 5 minutes.

Mix the flour and water together, then coat the chicken pieces with this batter.

Dredge the chicken in panko breadcrumbs, then pan-fry in a skillet with plenty of oil until golden brown.

Once cooked, drain the excess oil and set the chicken aside.

In a saucepan, combine the water, soy sauce, sake, mirin, sugar, and thinly sliced onion. Bring to a simmer.

When the onion is soft, return the chicken katsu to the pan and gently pour the beaten eggs over the top.

When the eggs are just softly set, serve the mixture over bowls of rice. Enjoy!