Possible Clues:

• Somen alternative
• Nagano noodles
• Noodle often sprinkled with sesame seeds
• Buckwheat noodles often served chilled
• Noodles in 112-Across, perhaps
• Thin Japanese noodles made from buckwheat flour
• Buckwheat noodle similar to udon
• Asian noodle
• "Buckwheat" in Japanese
• Buckwheat noodles in Tokyo