The Tale of the Antique Dealer: An Uramachi Sakaba Side Story

An offshoot of the near-future sci-fi stand-up bar manga "Uramachi Sakaba".
The main character is the antique dealer, one of the regular customers.
What strange phenomenon will he encounter deep in the mountains on his trip to Sedori!?
The owner of "Uramachi Sakaba" also appears in the story.
One volume, 45 pages.