There's a Sansotei on Dundas, and it always has lines whenever I pass by.
The Yonge location seems a bit more reasonable when it comes to wait times.
Or, just come outside of peak hours.
They have a simple menu: 6 types of bowls, a couple snacks, and some drinks and dessert.
Shoyu and Tonkotsu come with two slices of pork belly, while the others come with one. Of course, you can add a few extra slices of pork for a small fee.
There is an option to choose thick or thin noodles, but they all seemed pretty thin to me.
Broth is great. Noodles also have a lot of flavour from sitting in the broth.
I can see why so many people would be willing to stand outside for a spot.