When my yoga class was canceled recently, I decided to explore Yoga instead.

Yoga, in southwestern Tokyo's Setagaya Ward, was once a post stop on the old Oyama-Kaido pilgrims' road between the shoguns' capital of Edo (now Tokyo) and temples in the Mount Oyama area of present-day Kanagawa Prefecture. Today, it's a stop on the Tokyu Denentoshi Line about 20 minutes from the city center. When I emerge from the station, a sun salutation fittingly melts clumps of snow.

Passing several yoga studios, I choose a backstreet heading south through a low-rise residential area, a sort of suburban shavasana. Glancing down, I spy a basement window filled with art supplies. Someone inside beckons me. Husband-and-wife team Hirohisa and Yumiko Oyama run shop "all-square," a melange of scrapbooking and craft materials, plus handmade books and cards created by bookbinder and artist Yumiko, 54; and a self-publishing business Hirohisa, 58, runs in the back.

Yumiko's handcrafted books feature innovative closures, sewn and beaded bindings, and surprises inside. I pick one up. "Uh, that's not for sale," she says. I choose another. "Nor that one." My eyebrows climb. "I could make you copies to order," she suggests apologetically. My gaze travels instead to Yumiko's card decorations, made by rolling thin strips of paper into tiny flowers, cakes and animals. These she can part with, and as I buy several, Hirohisa offers to introduce me to their "interesting" neighbors across the street.

Koichi Kikuchi and his son, Nobuyuki, aged 69 and 40, are just emerging from sliding glass doors framed and decorated with patinated ironwork. "My creation," Kikuchi senior says, stroking the iron frame. Where's the studio? With a flourish, Koichi opens the doors to Kikuchi Kogyo, half garage, half blacksmith shop.

I admire the neat assortment of hammers, buffers and grinders, and a miniature firepot. "Recently, I've been creating these," Koichi says, handing me a twisted iron candelabra. "Take it, it's a gift." I demure, but he is already showing off another ornamented doorframe, featuring a scene of grapevines and an Italian palace. "Too bad this door just leads to the bathroom," he laughs.

Suddenly, something crashes overhead. Koichi cocks his head. "That's either my wife or melting snow."

Koichi, his son, and I all jog upstairs. Seventy-year-old Teruko knows why we've come up. "It wasn't me," she laughs, "it was snow." At her husband's urging, Teruko, once a seamstress by trade, pulls out baskets of her needlework. Though tsurushi-bina (hanging sewn charms to celebrate girls' or boys' day) are her forte, Teruko also fashions tiny goldfish, rabbits, cats, etcetera from bits of antique kimonos. "Aren't they amazing?" her husband asks. "Every detail is sewn, not glued or prefabricated. She's incredible."

The charms and brooches are impressive, but I especially admire the dynamics between Teruko and Koichi. Like an elderly couple from "long, long ago, in a place far away" — as Japanese fairy tales often begin — their mutual adoration is magical. Teruko tells me she's happy to offer a significant discount to any visitors, before her wares go to stores, and so I come to own a brooch of a rabbit in celadon silk bloomers.

Nobuyuki now asks if I'd like to see the smithy. Didn't I already see that? "Nope. It's underground," he says.

Back in the garage, Koichi pulls the car forward, while Nobuyuki cranks open a heavily insulated and rusted trapdoor. "You may not want to go down there," he warns. True that, but I do, clinging to cold rungs leading deep below the garage. In the gloom, three massive power hammers surround a sizable forge. All this for candelabras? "No," Nobuyuki tells me, holding up several steel rods with holes in them, "for arms and legs." I have an uneasy moment, but then realize he is referring to prosthetic devices. "My father has been supplying hospitals with the inner core of artificial limbs for 50 years," Nobuyuki says, as we ascend. "Will you do likewise?" I ask. He smiles and shakes his head, then shows me a cast silver ring he has made. Clearly, a creative impulse runs in the Kikuchi family blood.

With thanks, I head south again. At Kan-pachi-dori, I spot a storeroom filled floor to ceiling with chairs. Scandinavian Furniture Service, a shop devoted to vintage and gently used designer pieces, is holding its annual sale (up to 60 percent off, through March 27). Arne Jacobsen chairs, graceful tables, and even a jewel-blue Finn Juhl sofa wait to be purchased.

In the bowels of the shop, I find 25-year-old Tomoya Katsumata refinishing a table leg with steel wool and wax. "It revives quickly," he says, demonstrating how a few deft strokes restore the wood's depth. The shop will refinish any furniture you bring in (rates run about ¥35,000 for a four-seater table).

Further on, I'm ready for a break, but nothing prepares me for Sanga-no-Yu Seta Onsen, a hot-spring complex of idyllic rotenburo (outdoor baths), massage and esthetic services, restaurant and siesta rooms, plus a play zone for children.

Enthusiastic owner Shigetoshi Nagashima describes how he hired drillers to locate the lightly alkaline sodium chloride spring waters. "It was a gamble, but three experts told me it was down there. I prayed every night," he says. Finally, at 1,700 meters underground, he struck not oil but hot water the color of pekoe tea, enriched with ancient sea salts. "When I opened 14 years ago, I wanted a family-friendly place," Nagashima explains, pointing to the outdoor unisex baths (swimsuits required). "Three generations can enjoy this place. We're the only one like that in Tokyo," he says with pride.

Nagashima gleefully wades through squealing children in Pierette, the specially designed kids' play area. "A bath is where you clean your body, but an onsen (hot-spring bath) is where you clean your heart," he quips. Fran Hudson, a 43-year-old Tokyo resident who hails from Essex, England, agreed. "I come several times a year with friends for a soak, massage, and lunch," she says. "It's so relaxing, I find it's impossible not to nod off in the ladies' sleeping room."

Vowing to return, I head south again. Absorbed by the idea of heart-cleansing, I visit Tamagawa Daishi, a pleasant-looking Shingon Buddhist temple built in 1925 in honor of the renowned priest Kobo Daishi (774-835). I remove my shoes, go inside, and discover the temple has a tainai meguri ("womb pilgrimage"). Japan has few such underground tunnels, which are designed to make one appreciate the divinity of light by extinguishing it entirely for a time, and then to simulate the sensation of rebirth upon exiting. This one, dug in 1934, runs 100 meters long, 5 meters under the temple. I'm claustrophobic, but argue with myself that total darkness should render that irrelevant. I plunk down ¥100 and slip on plastic slippers. Then I procrastinate. Only when another visitor shows up and offers to go down with me do I venture into the steeply pitched narrow passage.

Seconds in, there is utter darkness. I cannot see my own hands, let alone my feet, and the air chills. My heart-rate flies off the charts, but I keep my left hand on the slick wall to anticipate where the next turn will be, and shuffle forward. I call out to my buddy, "This is like dogyo ninin, because 'we two walk together,' right?" I'm referring to the slogan pilgrims use to suggest that even if they walk alone, priest Kobo Daishi is with them. My friend laughs and I realize with panic she's way ahead of me. I'm in a womb of my own.

I set my slippers to high-speed, and finally emerge into a series of dimly lit chambers. In one, 300 stone Buddhas wait for their bells to be rung; in another, a two-meter, two-ton statue of Kobo Daishi carved from a single slab of stone gazes on a carving of Buddha reclining more blissfully than the sleeping guests at Seta Onsen.

My fleeting friend and I experience a mild sort of rebirth emerging from the dark, then drift our separate ways. Newly grateful for the late-afternoon light, I strike out for the Tamagawa River.

On the south side of Futako Tamagawa Station, a local strolling by points me to the area's two highlights. One, Isamiya Loco Works, is a model train hobbyist's heaven. Run by Isamu Ogawa, 75, the store carries nearly every train model part you could dream of, and some, such as tiny red shrine gates, that you didn't know existed. While I ogle the rolling stock, customers arrive and depart, though on select days, Ogawa tells me, fans gather on the second floor to "go loco" on his multitude of tracks.

As my engine runs out of steam, I walk the riverside road to its end, where two funky restaurants, Tokio Plage Lunatique and Gekko, huddle under pines and cherry trees that locals fought tooth and nail to save from a recent "development plan." After my underground journeys, I climb rickety steps up to Lunatique's rooftop, sip a glass, listen to birdsong and swaying bamboo at sunset, and find heaven.

Kit Nagamura will give a talk titled "Edo Melds with the Modern in Shitamachi," sponsored by the Brown University Club of Japan, on Sunday, March 13 from 1 p.m., inside Kiyosumi Garden (Kiyosumi-Shirakawa on the Oedo and Hanzomon subway lines). Open to the public, admission is ¥1,200.