Gov. Yuriko Koike may be taking Tokyo's "London of the East" dream a bit too literally, inking a four-year partnership agreement with the British capital.

Predecessors dating back to Shintaro Ishihara (1999-2012) long coveted London's energy, heft and influence in financial circles, wondering, well, why not us? Tokyo, after all, prints a top-three currency and boasts deep markets, more Fortune 500 companies than anywhere else, household savings almost comparable to annual U.S. output and world-class infrastructure.

Yet there are already a couple of problems with Koike's push to, as she says, get Tokyo off "Galapagos." One is joining arms with a city negotiating its own "Galapagosization" from Europe. How London emerges from Brexit with its financial-center street cred intact is anyone's guess. The more serious concern, though, is the tiredness of the ideas making the rounds.