Japan’s Spartan First Birthday Celebration – Isshou Mochi

My little monster is officially one year old! Over the past twelve months several of her major development milestones were highlighted with a corresponding Japanese tradition. But nothing could prepare me for the practice of isshou mochi (一生餅).

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 “Issho 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, and 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 New Year’s when it is served with miso soup in a dish called ozoni. Babies typically receive two mochi cakes in the traditional auspicious colors of red and one white.

The circular mochi typically has the character kotobuki (寿/longevity) written on it, but in recent years, it’s become common to have you child’s name written on the mochi. It’s also popular 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?


The isshou mochi box from Ojikaya comes with two mochi cakes and a cloth backpack, a happy birthday banner, and kinako (roasted soybean powder) for the mochi. 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 the monster’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 of issho 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

One baby 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.

If you’ve never touched mochi, freshly made mochi is very soft…while prepackaged mochi is as hard as a rock! There goes that Spartan/samurai spirit. Work those quads, baby!

Your Future Is in the Cards – Literally

After the crying fest of 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 want an isshou mochi set for yourself or as a gift, click on the image below to access the Rakuten shop for Ojikaya. (link in Japanese).

Check out my other posts on Japanese celebrations for baby:

Baby’s First New Year – Hatsu Shougatsu

Baby’s First Christmas – Hajimete No Kurisumasu

Half Birthday – Celebrating 6 Months of Life Together

Okuizome – An Elaborate Feast for Baby

O-Shichiya & Meimei-shiki – Japanese Baby Naming Tradition

O-Miya Mairi – Taking Baby to a Shrine

Inu no Hi – A Shrine Visit for Pregnant Women

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2 thoughts on “Japan’s Spartan First Birthday Celebration – Isshou Mochi

  1. Very interesting, i didn’t know about this custom.
    I love you daughter’s name by the way 😉 Don’t know if you forgot to blur it or not. It’s blurred at the beginning and not when she stomps on the mochi. Oh well, regardless, it’s beautiful, classic and easy to pronounce in Japanese 😉

    1. Thanks for catching that! I wanted a name that would easy to pronounce and spell for English and Japanese speakers.

      It seems like this custom isn’t so well known. My in-laws really care about these traditions, so I learn a lot!

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