Commemorating the 100th anniversary of the city, the manhole features the Hori River and Naya Bashi (納屋橋).
100 周年を記念して、名古屋市の中心部を流れる堀川と広小路通が交差する「納屋橋」
This looks awfully similar to Fukuoka City’s manhole design. Clearly someone was influenced by someone else.
The older manhole covers feature an amenbo or "Water skipper" (gerridae).