For a city of its size and density, Tokyo is disproportionately lacking in great sandwiches. Let us be clear: We’re not talking about ethereal Japanese-style sando, with their soft white bread and fillings like omelet, strawberries and cream or even ridiculously expensive wagyu fillets (although those are a perfectly valid and wonderful form of sandwich). We’re thinking of hearty sandwiches that power you through endless Zoom meetings: baguettes, toasties, wraps, banh mi. Fortunately, there’s the Chipper’s pop-up at BathHaus, where Kohsuke “Chan” Yamaoka turns out simple, well-made sandwiches every Tuesday evening.