Mizukoshi
A well-known miso nikomi udon specialist in Kamizato, Okazaki, using miso from the historic Maruya Hatcho Miso brand for its rich, simmered noodle broth alongside a famous miso katsu. Winters bring packed houses of regulars night after night. Noodle firmness can be adjusted to preference.
Over 100 Tabelog reviews (3.39) and 45 on CookDoor. Local blogs repeatedly describe it as 'exceptional miso nikomi udon' and note it's 'extremely crowded'—winter waits and full houses are the norm. The miso katsu is also well regarded.