There are plenty of good restaurants in Asakusa, but the better the place, the more likely it is to close between lunch and dinner. I missed the lunch hour and tried to walk into a restaurant around 1:30, only to find most of them open until 2 at the latest, so I went to the most mainstream place there is, right in front of Kaminarimon.
Kashiwa seiro
Cold soba you dip into a broth with chicken in it. Usually it is duck, but here it was chicken. The taste was ordinary. The soba in particular was overcooked and lacked bite.
Jumbo shrimp tempura soba
The shrimp was fine, but the soba was not great here either. I should have gone somewhere quieter instead of a place tourists flock to, which is a shame. I also wondered whether the tendon or the tempura set would have been the better choice over soba. But I am on a diet these days, so I could not order anything like that. Next time I will take my time and look for a proper good restaurant.