By the door hangs a paper chart bearing ink-drawn images of men and women, their aches and pains indicated in red - this belongs to Mrs Shinano who works as an acupuncturist alongside her husband. On a broad table, leaves, grasses and shards of bark in various colours are in the process of being ground up and labelled.
But it is to the contents of the thick glass jars that the eye is drawn - a long, yellow bone, disturbingly human-looking, and three dark, shrivelled tubers floating in fluid.
They come from across the sea; between them they must be worth several thousands of pounds. They are the femur and penis of the Chinese tiger, and it is men like friendly, red-faced Mr Shinano who have brought it to its present plight, with as few as 20 animals surviving in the wild.
Traditional Chinese medicine is a thriving business in Japan and within five minutes' walk of Mr Shinano's shop can be seen a zoo of dismembered, pickled or desiccated breeds used in the concoction of its pills, salves and tonics. A nearby shop displays deer penis, monkey hand, bear's gall bladder and bees preserved in sake.
In pharmacies in other parts of Tokyo are found rhino horn, monkey head, narwhal tusks, whale foetus and the penises of seals, wolfs and sea lions. But for the traditional apothecary, it is the tiger - its bones and genitals, and the pills and tinctures derived from them - which is prized above all, and for which customers will pay the highest prices.
The bones are regarded as a potent remedy for rheumatism, the penis as a natural aphrodisiac ("It's just Viagra!" proclaims the sign in the window of another shop). A week's supply of 100 tiger bone pills costs 3,600 yen (pounds 20), tiger bone sake is pounds 55 a bottle.
But the tiger, as everyone knows, is a gravely endangered species. Since 1980, Japan has been party to the Convention on International trade in Endangered Species (Cites) which bans the international trade in tiger parts. How can the apothecaries of Tokyo get away with such open flaunting of international rules?
"It's OK to kill tigers for use in these pills," explains Mr Shinano - but it is certainly not.
In June 1997, the Cites conference adopted a resolution urging signatories "to adopt comprehensive legislation and enforcement controls as a matter of urgency, with the aim of eliminating trade in tiger parts and derivatives, in order demonstrably to reduce the illegal trade".
The Japanese government excuses itself from this responsibility with a legal loophole. Japanese law fails to ban the trade in tiger parts which are not "readily recognisable". And no restriction exists on tiger products designated "pre-convention" - in other words killed and imported into Japan before 1980.
In other words - unless they have whiskers, stripes and big teeth - it is legal to buy, sell and possess tiger bits in Japan.
Existing stocks, the government insists, are "pre-convention", but the only guarantee of this is a voluntary system administered by the traditional medicine industry itself. Remarkably, Japan's own trade statistics show the vigorous trade in tiger parts: between 1990 and 1992, according to official statistics gathered by the London-based Environmental Investigation Agency (EIA), 70 tons of tiger-based products were imported into Japan.
"The treaty is undermined and threatened by the failure of the Japanese government," the EIA concluded in a report last year. "Every day ill-equipped forest guards risk their lives against the poachers. Final responsibility for the gun battles ... rests with the consumers."
None of which impresses Mr Shinano. "Whether China is killing them or not is not our problem," he says. "It's the Chinese government's problem, it's for them to deal with." And the Cites treaty, he points out, has made one big difference.
"Three or four years ago, you see, we used to call these `Tiger Bone Pills'," he says. "But now we've changed the name to `Muscle Pills'." The contents are exactly the same.Reuse content