Since coming to Japan, I have fallen in love with tenzaru soba. I first had zaru soba on a hot summers day in Osaka with my host family, but it was in Nagano that I first had tenzaru soba. Tenzaru soba is a bunch of chilled soba noodles served on a bamboo tray accompanied by a dipping sauce and tempura. The only difference between tenzaru soba and zaru soba is that tenzaru comes with the tempura.
I have had tenzaru soba twice since arriving in Nagano (Nagano prefecture is also known for its soba), once in Togakushi and a second time in Minakami (Gifu prefecture). It is sooooooo good and is perfect for hot days.
After you are done eating your meal, you will sometimes be brought a small pitcher. It is filled with the water your soba was boiled in. You pour it into your left-over dipping sauce and drink it; this way you get all of the nutrients and things that left the soba noodles when they were boiled.