Asago City is located in the Northern part of Hyogo Prefecture. The symbol in the middle is the City’s flag, its not that clear but it is supposed to be a mountain with a sun on the top. So that triangle is for the mountain and the circle surrounding it is the sun.
I guess based on the amount of Cherry Blossom, you already know that it is the city’s flower symbol.
Till the next manhole edition 🙂