In a medium sauce pan, combine soy sauce, mirin and sugar. Heat just to boiling (to melt sugar). Remove from heat and allow to cool. (Place in refrigerator until chilled).
Boil somen according to package directions. Drain somen in collander and rinse well with cold water.
In a large serving bowl pour drained, cooled somen. Add to the somen, a cup or so of water, and a couple handfuls of ice cubes.
In separate small bowls (about the size of a ramekin) pour about 1/4 cup of the cold soy sauce broth.
Serve family style, and add small portions of somen to the soy broth at a time... enjoy, repeat, enjoy!