Swap Tokyo’s steel skyline for the secret city under its tracks. In Shimbashi a lantern-lit alley coils like a hidden base: every few steps a sliding door reveals a stand-up bar where yakitori hisses and salarymen teach you to shout “Otsukare-sama!” over ice-cold beer. Walk on and the scenery keeps mutating—sake dens turn to noodle stalls, vinyl dive bars, charcoal grills—until the lane pours into Yurakucho, a brick-arched cavern glowing with retro neon. Here the pace softens; cedar cups of regional sake clink as commuter trains rumble overhead and chefs ladle stews perfected since the 1960s. Three to four drinks and classic bar snacks are included, but the real treasure is the lore your guide unlocks: a grill master who has guarded the same counter for fifty years and a retiree whose enka echoes whenever a bottle empties. Arrive curious, leave smoky, and carry home a map of Tokyo nightlife few visitors ever find.