John Mayer at AIRS in Tokyo

John Mayer visited a store in Shinjuku, Tokyo, Japan called AIRS, which is a record store (which also sells bootleg films, CD's, etc).

Many, many, many other celebrities have come here, but I was on a mission to find John's, knowing he was here

The full message he wrote was:
"I am now 26% cooler for having been here."