Motherhood & Parenting in Japan

Japan’s Spartan Baby Tradition: Isshou Mochi

Last Updated on 2024-01-08 by Teni

Japan‘s spartan baby tradition, Isshou mochi, is a 1st birthday celebration. Basically, you strap 2 kilograms of mochi to a toddler and delight in their cries and falls. Oh, and there’s a divination game that determines your child’s destiny.


I’m not making this up.

Several of my daughter’s  major developmental milestones were highlighted with a corresponding Japanese tradition. But, nothing could prepare me for Japan’s spartan baby tradition: isshou mochi.

To begin, I had never heard of isshou mochi. So when my husband told me he’d ordered an isshou mochi set, I thought “Yes! Instant blog topic and material for my Instagram! I mean… Yes, a wonderful opportunity to learn about the customs and culture of Japan.”

What Does “Isshou Mochi” Mean?

Isshou mochi (一生餅) refers to the antiquated unit of measurement called a shou. One shou (一升, isshou) is equivalent to 1.8 kilograms, or nearly 5 pounds. Students of Japanese know that the language is fond of linguistic puns. Isshou is also how you pronounce the kanji 一生, meaning “one’s entire life.”

Mochi (餅) is Japanese rice cake. Rice cake makes several appearances throughout the year in Japan, most recently during the Japanese New Year when it is served with miso soup in a dish called ozoni.

For isshou mochi, babies typically receive two mochi cakes in the traditional auspicious colors of red and one white.

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Teni Wada | Baby Kaiju Blogさん(@wadateni)がシェアした投稿

The circular mochi typically has the character kotobuki (longevity) written on it. But in recent years, it’s become trendy to have you child’s name written on the mochi. It’s also customary to get pink heart shaped mochi for girls, because it’s kawaii (可愛い | cute).

Presenting a baby with isshou mochi can be interpreted to mean that they will have enough food for the rest of their lives, or that they will never run into difficulty producing food.

So what’s so bad about giving a baby 2 kilograms of mochi?


Inside the isshou mochi box was two mochi cakes and a cloth backpack. In the olden days families used a furoshiki (風呂敷), a traditional cloth used to wrap bentos and gifts that also functioned as an origami-like bag.

Inside the cloth backpack went both mochi cakes, and the cloth backpack went on my daughter’s back! This is called seoi mochi (背負い餅), carrying mochi on one’s back.


A one year old weighs, on average, 8-10 kg. Why on Earth you would make them carry a quarter of their weight, especially when many of them can barely walk or are learning how to walk?

Here’s another peek at Japanese culture:

In some regions, parents and grandparents are delighted if a baby can stand on their own, but in some regions, a child that can carry the mochi on their own is destined to leave the family nest early. In fact, families in those regions even go out their way to nudge the baby so that they’ll topple over!

Guess which group my husband belongs to?

Truthfully, I suspect that the custom isshou mochi has something to do with the deep Japanese cultural notions of gaman (我慢, perseverance) and ganabare (頑張れ, “do your best!”).

This seems like a good PhD topic — if I could be bothered to put myself through the stress of graduate school all over again!

If You’re Happy and You Know It, Stomp Your Feet

Miss M had successfully (unsuccessfully?) shouldered her burden of mochi, it was time for mochi fumi (餅踏み), stepping on mochi. This part of a baby’s first birthday originated in the Kyushu region. Oftentimes, waraji (草鞋) straw rope sandals are worn during this part of the festivities.

Your Future Is in the Cards – Literally

After the crying fest that was seoi mochi, it was time for some divination. The mochi set that my husband purchased also came with a set of cards featuring objects that represent a career path or personality trait.

During this “game” of erabitori (選び取り), the first card that a child touches is their calling. Between husband and I, the jury is out.

While she technically touched the violin card, in my opinion, she pushed it out of the way and headed straight for the mirror. Who knows? Maybe she’ll be a very talented and beautiful musician.

If you’re currently in Japan and would like to get an Isshou mochi check out this set on Amazon Japan. This set comes with a cloth backpack, mini mochi bites, and divination cards. What makes this set special is that the erabitori cards have QR codes on them, so you can scan them and take fun birthday photos together!

For more on other Japanese celebrations, I recommend this book, Japanese Traditions: Rice Cakes, Cherry Blossoms and Matsuri: A Year of Seasonal Japanese Festivities:

Available on Amazon & Amazon Japan

Japan’s Spartan Baby Tradition: Isshou Mochi

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