I spent whole this week in Shinagawa.
I stayed in the Shinagawa Prince Hotel and there was a nice ramen restaurant area called Shinatatsu, meaning Shinagawa ramen masters.
There are 7 popular ramen restaurants and 5 bowl restaurants as well.
And they have foreign visitors friendly system.
All you need is to buy a ticket at the vending machine with pictures and present it to the restaurant staff. Then you ramen will be brought to your table. Easy isn’t it?
Shinatestu is just a few minutes walk from Shinagawa station. From west exit, turn left and you will find it underneath of the train railway.