Babies' skin is very delicate. They move around a lot, so they sweat a lot. Underwear that protects against various irritants and absorbs sweat effectively is important for a baby's healthy skin and comfortable life. We spoke to Kana Hino, a maternity and baby concierge and stylist in charge of newborn clothing at Isetan Shinjuku, about how to choose newborn underwear.

How many newborn underwear do I need?

I'm often asked whether it's necessary to buy multiple sets of newborn underwear that will soon be outgrown. However, newborns have difficulty regulating their body temperature. It's important to wear enough underwear to keep them warm. Babies also sweat just as easily as adults, so they may need to change their underwear multiple times throughout the day. They'll also be breastfed frequently, spit up, and get soiled from diaper changes, so it's a good idea to prepare extra underwear. It's a good idea to have around five to seven layers on hand when preparing for birth.

Do I Need to Dress in Layers?

For babies who have trouble regulating their body temperature, we recommend dressing them in two layers. You can think of the bottom layer as what we'd call underwear for adults, and the top layer as clothing. Even in the summer, when you're in an air-conditioned home, it's a good idea to layer your clothes.

Differences Between International and Japanese Brands of Underwear

International brands of baby underwear often have a slim fit with button closures, while Japanese brands tend to offer short, drawstring-tie undershirts or combination undershirts. Since you don't need to fasten multiple buttons, it's easy to get changed. This is a recommended type for those who aren't yet used to dressing themselves, as it allows for quick changes.

What Material Should I Choose?

There are many different types of underwear fabrics, but rib knit is a material that can be worn year-round. Rib knit underwear is stretchy and absorbs sweat well. In the summer, thin, smooth jersey fabrics and quick-drying mesh fabrics become available, so you can combine these in hot weather. In the winter, wool and cashmere underwear are also popular.

Now that the temperature in your home is more comfortable, you may not need particularly warm or quick-drying fabrics. We hope you choose underwear that suits your lifestyle. At Isetan (Shinjuku branch), you can choose from a variety of brands and materials, and we carry sturdy materials that retain their shape and remain durable even after repeated washing. We also have concierges like me who can recommend underwear that suits each individual's lifestyle.

Introducing Underwear Recommended by Our Concierge

Here, we'll introduce newborn underwear recommended by our concierges. You can rest assured that all underwear is made by Japanese brands that are particular about materials and construction.

■ "Familiar Romper Underwear"



A distinctive feature of Familiar underwear is that the seams are on the outside, which means they are less likely to lose their shape and do not wrinkle even after washing. Familiar romper underwear is convenient as it can be worn alone even in the summer, and it also has a secure fit. This type has an embroidered bear, and is popular for its soft, baby-like colors.


■ "Baby Castle Smile Cotton Underwear"


Smile cotton is a material also used in adult underwear. It is fluffy, soft, and highly absorbent. It remains soft and fluffy even after repeated washing. Baby Castle underwear also has tightly sewn seams to prevent irritation to the skin. Smile Cotton underwear is plain, but the pattern does not show through when wearing clothes over it, so we recommend bringing plain underwear with you.


■ "Sense of Wonder Organic Cotton Underwear"

This underwear is made from organic cotton. While organic cotton is also used in adult clothing, it is a material that is recommended for those with sensitive skin. Sense of Wonder's organic cotton underwear features adorable prints, making it a great choice for those who enjoy unique patterns and designs. It also opens in the front, making it easy to put on and take off.

We've introduced recommended underwear for newborns. Choosing underwear depends on the season of birth and your home environment. For first-time parents, you may be unsure of what to choose.


Isetan Shinjuku offers a maternity and baby concierge consulting service. We're here to help with any concerns or worries you may have about your first pregnancy or childbirth. We're here to help you and your family with advice on your body and baby during pregnancy, as well as choosing products like strollers. You can visit us in person, but we also accept reservations online.