I might be allergic to sake, I inform Paul Jones as he shrugs off his jacket and sits down at the absurdly large table at the Oak Door, a wood-panelled, upmarket steakhouse in Roppongi Hills in downtown Tokyo.

We have been ushered into a private room, away from the hum of bankers and lawyers’ pre-Christmas lunches. The crowd is full of beautiful bespoke suits but is getting rowdy. Business drinking is like an Olympic sport in Japan.