Tenmusu are Onigiri rice balls with shrimp Tempura as a filling. Onigiri is rice shaped by pressing firmly in your hands and forming into a ball or triangle, or some other kind of shape. Typical fillings are pickled plum (Umeboshi), dried bonito flakes with soy sauce (Okaka), or salted salmon. Tenmusu is something special, with Tempura shrimp and all. It’s kind of like the “go-to” Onigiri for important Onigiri.
Tenmusu is known as one of Nagoya’s (Aichi prefecture) regional foods, but it actually originated at a Tempura restaurant in the Tsu area (Mie prefecture). Tenmusu was first created as employees’ meal at the restaurant in the 1950s. Later, a branch was opened in Nagoya and became very popular by the 80s. Tenmusu has spread widely today, and you can buy it in many Onigiri shops all over Japan.
The size of Tenmusu is a little smaller than normal Onigiri (although you can make any size you like), so it may not be able to hold a whole shrimp, depending on the size of shrimp. We cut the Tempura shrimp in half. That still has enough length to show the end from the top of Onigiri, which is the signature look of Tenmusu. We use Tempura sauce (our multi purpose sauce, Mentsuyu) as a seasoning, but just salt works too if you prefer.
- Cut the sheet of Roasted Seaweed into 1/4 strips. Cut shrimp Tempura in half if too big.
- Season Steamed Rice lightly with salt.
- Start making rice ball (watch Onigiri video), dip shrimp in Mentsuyu, and place it in the middle of rice. Shape Onigiri into a triangle, with the end of the shrimp peeking out of the top corner. Wrap with a strip of Roasted Seaweed.