“Toddler” and “shopping” are two words that are likely to instill instant fear into the heart of all but the most unflappable of parents.

There are perhaps few less relaxing tasks than navigating the shops while lugging a young child who would rather be playing, running around — anything, in fact, other than sitting in a buggy watching their mother ponder which brand of tofu or what color bath towels to buy.

Grown-ups often simply want to shop quickly and efficiently, but toddlers tend to have another idea in mind: They would much rather free themselves from their buggy, David Copperfield style, before emptying the contents of shelves onto the floor or showing off their window-shattering vocal abilities by having a tantrum.

This, it seems, is where Muji is keen to step in. An urban oasis of calm, its signature rows of plastic shelving, neutral wood furnishings and neat piles of white T-shirts are always instantly soothing — for this frazzled parent in particular.

And recently, the minimalist Japanese store has been offering services to attract parents with small children.

Firstly, there are a growing number of beautifully designed wooden play spaces opening inside its stores across Japan (27 at the latest count), where children can slip off their shoes and run around playing with instruments, crayons, wooden toys and baths of cypress-wood eggs.

And secondly, it has launched a baby-sitting service — called Mokuiku Room — in the shiny new multi-storey Muji store that reopened in Shibuya Seibu last November, with the goal of allowing parents to leave their children in professional care while they shop in peace.

“We hope to make more wooden play spaces in our stores,” says a spokeswoman for Muji. “We hope that both parents and their children will have a good time while shopping at Muji stores.”

It was with a sigh of relief that I recently made my way to the fifth floor of the Shibuya store. Here, the entire space is devoted to all things baby and child — from baby clothes and maternity wear to feeding accessories, books and toys.

Best of all, center stage is a wooden play space. My 1-year-old daughter, who was already showing signs of restlessness in the lift on the way to the fifth floor, was delighted to be set free.

She kicked off her shoes and tentatively wandered around the edges as she watched several older children drawing pictures at a little wooden desk — before losing her inhibitions as she examined a wall covered in green leaf magnets.

Meanwhile, I was able to happily indulge in some shopping, perusing the childrenswear and toy sections in unaccustomed peace, while keeping an eye on her playing at the same.

It was while I was standing in the toy section, looking at an inventive cardboard teepee (and my daughter was leaping head-first into the wooden ball pool), that I spotted a sign for Mokuiku Room.

A peek behind the wooden doors revealed a decorated space with padded floors, neatly arranged toys and a small team of professional, smiling childcare staff waiting for the first booked arrivals of the day.

Muji has joined forces with baby-product maker Pigeon to provide professional staff, with parents able to book spots for children ranging from 6 months to 6 years at a cost of ¥1,080 an hour, for a maximum of three hours. (One hour is free if you spend ¥3,000 or more in the shop.) It opens Friday to Monday every weekend, from 10 a.m. to 6 p.m., with a limited capacity of up to eight children at a time; bookings are essential.

On this particular occasion, as I was visiting Muji to shop specifically on the fifth floor, I was happy enough to let my daughter play in the communal wooden play space rather than drop her off with childcare staff. But it’s a service that is definitely worth bearing in mind for parents who want to indulge in some speedy shopping either in the store or nearby in Shibuya for a few hours. The perfect solution for toddler-tantrum-free shopping.

Muji Shibuya Seibu store: 21-1 Udagawacho, Shibuya-ku, Tokyo. Mokuiku Room reservations: 03-3770-1636, www.muji.net/shop/service/woodroom.html. For more information about children’s services in Muji stores across Japan, visit www.muji.net/kids.