Make hard boiled egg and peel the shell while it's still hot. (Quickly run it under tap-water and peel the shell off while the surface of the egg is cool so you don't burn yourself. Don't cool the inside of the egg.)
Shape the egg into the shape of the Nameko while the egg is still hot and soft. Use fingers to pinch the egg to make the pointy part. Flatten the top and bottom of the area by sandwiching it with two fingers.
It looks like a Nameko when you make the mushroom top part pointy. Once you've shaped the egg, cool in cold water while holding the shape with your fingers. (The egg will harden when cooled.)
Add color to the boiled egg. Add mentsuyu and soy sauce (1 : 1) into a cup. Insert the skewer into the thin end of the Nameko (the leg part) and place into the cup with the skewer pointing out.
Adjust the skewer so that the egg is half way dipped into the mixture. Adjust the height by using the chopsticks to pinch the skewer to hold it in place. (This is a key point!)
Let it sit in the refrigerator for about an hour. (Since I did this before heading to bed, mine sat for 5 hours. Make sure to leave it in the fridge.)
Remove the skewer. Slice the back off so it won't roll over. It makes it easier to do the next steps. (This piece will be used for the next step.)
Thinly slice the white yolk (the piece from the back) and use a knife to cut shapes as seen in the picture. (Mouth, arms, and legs) It's easier if you use rabbit shaped cookie cutters for the legs.
Cut the nori seaweed into shapes (as seen in picture) using scissors. Carefully place a thin layer of mayonnaise on the back of the nori seaweed and attach it onto the boiled egg. Place the arms and legs as well.
It's complete! The Nameko will stay in place if you insert a thick pasta in the back. (It will absorb moisture and become soft by the time you eat it.)
This is a version without shaving the back, without the arms and legs. It's easy.
Story Behind this Recipe
After talking with my Nameko-loving-son on how to make the Nameko look more shiny for days, we came up with this. The skewer and chopstick technique used to brown half the egg was a borrowed idea from a summer research project making plastic food. Thanks to this, we were able to make a realistic and cute bento!
Be careful not to break the egg white by pressing too hard when shaping the egg! Other than preventing the cup from spilling over, the skewer and chopsticks helps keep the egg from touching the bottom or leaning on the side of the cup. When the egg is touching the cup, it doesn't color the egg very well. If you're making it for a bento, it's better to shave off more (on the back) so it won't stick to the lid.