Shigeru and Kazuhiro Yamaji are father and son who run separate used-book stores in an old commercial building owned by the family in noisy Shibuya, amid the rampant juvenile shoppers and smoke and steam billowing from yakitori bars and ramen stands.

Crowds scurry around the scramble crossing. Touts for hostess bars loiter on the stained greasy streets like the wafting smells of grilled meat. On nearby “love-hotel hill”, rooms can be had for a few thousand yen an hour.

Shigeru, 71, has gentle, intelligent eyes and silver hair. His shop with its faded lino and fluorescent lighting has traded at this spot since 1957. It goes by a couple of names, either Shibuya Kosho Center, or Kosho Sanei. But the name is not important. To regular customers, the store is beyond branding, like a plain glass of water on a hot day. Books are all there are. Books outside on trolleys, books to the ceiling inside. Books piled in towers on the floor, bound in plastic ribbon, waiting to be appraised.

Enter the store by a sliding door on the right or the building’s main door on the left, which takes you into a narrow stairwell. Downstairs is a DJ bar that serves Taiwanese food. To the right, Shigeru’s shop has no wall, there are only bookshelves facing into the hallway. Foreign books are here. Sun-bleached volumes by Graham Greene, Ted Hughes, Mickey Spillane, English translations of Roland Barthes, the adventures of Maigret. Most cost around 400 yen.

Almost everything else is in Japanese. Plenty of art books and artist monographs. Back issues of cultural magazines and architectural journals. Robust porno with titles like Other Men’s Wives (including DVD!). There are no decorations, save for a few ukiyo-e woodblock reprints of sultry courtesans (also for sale). You get the sense if you took away the books, the room would evaporate.

Shigeru aims for fast turnover, like his mother did; she took over the shop at their one-storey home across the road from 1947, right after the war. Her husband died when Shigeru was aged one, so she brought him up at the store. Shibuya was already a centre for cheap shopping and nightlife, with the added colour of the Occupation and the black market. Shigeru says there were used bookstores up love hotel hill, where you could buy the traded-in correspondence of famous artists such as Yumeji Takehisa. There were also people who offered English-language love-letter writing, for women who had fallen for American GIs.

Shibuya was already a centre for cheap shopping and nightlife, with the added colour of the Occupation and the black market.

Shigeru joined his mother in the trade after working a few years at a nearby Russian restaurant. They moved to their current site in the late 1950s, when the government began “purifying” the area for the 1964 Olympics. Shigeru’s mother was a good businesswoman and the store thrived through the breakneck economy of the ’50s and ’60s.

There’s less demand for used books now. “I want to get young people back into reading,” he says. “Many books I used to sell for a thousand yen, I’ll sell for 500 now.” His bestsellers are arts, self-help and popular philosophy.

Upstairs, Flying Books presents a dramatic change. Kazuhiro, 44, came up with the name when he was learning to pilot a light aircraft after going skydiving for the first time in Brisbane, Australia. Now in its 16th year, Flying is sleek and warmly lit, with plenty of timber, a counter serving espresso and in the centre of the room, two rolling shelf units that can be moved away for events. Photobooks and counter-culture dominate, but there are all genres. Perennial volumes on the shelves include the Whole Earth Catalog and photobooks by the likes of William Klein, Daido Moriyama, and Martin Parr.

I saw all the big data. My job was to make a profit. But that makes for a boring selection…it makes nothing for people’s hearts. I saw some good independent bookstores and I wanted, if I had a shop, to do it like them.

“Running a bookstore is like editing a magazine,” says Kazuhiro. “It’s not about following genres, it’s more like curating, it’s about what you choose.” Flying’s books are more likely to be rare, fashionable, and international than those downstairs.“I didn’t want to join the family business at first,” says Kazuhiro. “I had a job at (rental video and CD chain) Tsutaya for three years. I was a buyer of music, movies, and new books. I saw all the big data. My job was to make a profit. But that makes for a boring selection…it makes nothing for people’s hearts. I saw some good independent bookstores and I wanted, if I had a shop, to do it like them.”

Solidly built with slicked back hair, a trimmed goatee, and good spoken English, Kazuhiro is a true international entrepreneur, as fluent with Asia as he is with the West. He makes regular buying trips to the US, consults for fashion houses and bookstore operators in Japan and China, has contacts through Thailand and Indonesia and runs a publishing imprint as well as producing CDs.

He has lived on an island commune off southern Japan, and knows the Zen-Beat forefathers like Gary Snyder and the Japanese poets they inspired. Tetsuo Nagasawa (pictured), the “Rimbaud of Shinjuku” from the 1960s, gave a reading there recently. It has become an annual event, before he returns for the flying fish season to the small island off Kagoshima where he lives.

The contrast between Kazuhiro and his father is striking, but they are alike, and easy in each other’s company. They attend book auctions together and collaborate on buying. “My father’s age is good for what he does,” he says. But I can’t do it like that. My era is more about buying the right books than selling books.”

The two stores offer more than books; they contain a head-swirling microcosm of the world. This may strike you down on the street, among the parade of potential idlers and artists, students and fashion victims, cooks, prostitutes, businesspeople, Zen priests and philosophers.

Like used books on the shelves, each one is unique, and if the pages are worn, that is also their value.

A version of this story appears in the current Mekong Review