Trying to recommend ramen in Japan is like recommending chicken rice places in Singapore - bad ones are harder to find than good ones.
There are so, so many good ramen places everywhere in Japan, I hesitate to write up and recommend any but this one in Kyoto I really like and would go back again.
But, I have to forewarn you that it is not for everyone as it is very rich and on the sweet savoury side.
It's the feel and flavour profile I like for ramen.