What is one of the reasons Eifukucho Taishoken became so famous?
Ice water.
Many decades ago, in the shop's early years, business was slow. The master decided to try something no other ramen shop did. Instead of tepid tap water, the norm, he bought an expensive ice machine and gave customers free flowing ice water alongside his hot bowls. Tokyo summers are brutal and the idea was a hit. Instant line around the block.
They still keep your glass full of ice water and offer to top you off after a few sips. Less