meaning "ladder", however, has the slang
meaning of drinking in 3 or more places in one night. The number of places gone to in one night is measured by the counter word ken. 1 ken, 2 ken, etc.
All masters strive to attain new heights in the "ladder"; the art of hashigo. All salaryman must study hashigo, however, being a kyuuryou dorobou, I must be a master of the art of hashigo. I am a proud 6th degree master of this arcane art, my personal best is 6 ken in one night in 2 cities, Sagamihara and Kawasaki all in a 12 hour drinking spree. This was all after a full day of work and despite having to work the next morning.
All good pupils of the art of hashigo must become acquainted with, and contemplate the phrase "mo ikken?" (meaning "You wanna go 1 more place?") and consult their masters about this before leaving sacred temples and shrines called izakaya.
The word hashigo is written in katakana. It is written in Japanese fonts at the top of this writeup so you might experience mojibake.