<figure id="attachment_458906" aria-describedby="caption-attachment-458906" style="width: 800px" class="wp-caption alignnone"><a href="#" data-ident_hash="0722d117"><img src="https://res.cloudinary.com/fridaydigital/image/private/t_article_image/wpmedia/2026/02/1401568905912f39d8ccfcd6af099ad8.jpg" alt=""></a><figcaption id="caption-attachment-458906" class="wp-caption-text">Clockwise from upper right: Diphthong tree frog, Tonosama toad, Azuma toad, and Mori green tree frog. There are 54 species of frogs in Japan alone (from &#8220;48 Frogs of Japan: An Eclectic Illustrated Book&#8221;).</figcaption></figure>
<h3><span class="strongInContent"> The more you know about them, the more you like them.</span></h3>
<p> With their round, round eyes, smiling mouths, and stocky bodies, these frogs are cute to say the least. On the other hand, her sticky skin texture is also poisonous. If we say they are disgusting, we might be right. Frogs are strange and contradictory creatures.</p>
<p> Takahiro Sakono&#8217;s love of frogs has led him to observe almost all species of frogs distributed in Japan in the field. While studying the reproduction of deer, monkeys, and other mammals at the University of Tokyo&#8217;s Faculty of Agriculture, he joined the University of Tokyo&#8217;s Biology Research Group and began his journey in search of frogs. His hobby led him to publish &#8220;48 Frogs of Japan: An Eclectic Illustrated Guide&#8221; (Kawade Shobo Shinsha), which contains his own exquisite illustrations and commentary. A new edition of the book was published in January.</p>
<div data-friday-ad-slot="AD_inArticle"></div>
<p><span class="strongInContent"> Frogs are the only vertebrates that change so much from larvae to adults. As they grow from tadpoles, their tails disappear and their limbs grow longer. In addition to changes in form and function, their habitat, diet, and behavior also change.</span></p>
<p><span class="strongInContent"> Tadpoles are aquatic, but some adult species live on trees using suckers. Frogs cannot swim across the ocean, and their appearance and genetic characteristics differ in various regions. New species have been discovered, and at the time of the first publication of this book in June &#8217;20, it was thought that there were 48 species, but the number has now increased to 54. The more you know about them, the more you like them, and the more you are fascinated by the depth of the frogs,&#8221; (Sakono also made the following comments).</span></p>
<div data-friday-ad-slot="AD_inArticle"></div>
<p> The common image of frogs&#8217; croaking is &#8220;kerokero,&#8221; but in reality, it varies from species to species. In reality, however, the frogs vary from species to species, and the Nebatago frog was discovered in Neba-mura, Nagano Prefecture, after a rumor circulated that <span class="strongInContent">there was a frog that croaked</span>.</p>
<div data-friday-nextpage-lead=" Some frogs raise their young as a couple!"></div>
<h3><span class="strongInContent">Frogs have been loved since ancient times</span></h3>
<p><span class="strongInContent"> The frog is distributed in limited areas such as Aichi and western Shizuoka prefectures, and its high-pitched, puppy-like voice makes a &#8220;woof, woof, woof&#8221; sound. During the breeding season from April to May, females walk around looking for males, so it is relatively easy to spot them at night along streams.</span></p>
<p><span class="strongInContent"> Genetic analysis of frogs began around 2010, and in 2002 it was discovered that the nevatago frog and the tago frog are two different species with different numbers of chromosomes. Although not as doggy-like as the nevatago frog, the tago frog also sometimes croaks. Since they are not identifiable by their appearance, the nevatago frog was previously thought to be a tagog frog.&#8221;</span></p>
<div data-friday-ad-slot="AD_inArticle"></div>
<p> Other frogs in the family include the Kajika frog, which has a beautiful deer-like cry, &#8220;Fee, fee,&#8221; and was sometimes kept as a pet during the Edo period (1603-1868).</p>
<p><span class="strongInContent"> The frog is a member of the family Ooïidae and lives in rocky areas such as mountain streams. In the &#8220;Kyuai Zuitsu&#8221; (Essays on the Oi and the Dust) of the mid-Edo period, it is written that it is a taste of the fengryu people to love the sound of the frog&#8217;s cry, and it also describes how to keep the frog. The name &#8220;kawaka&#8221; was written in Chinese characters and a special case for keeping the animal, the kawaka cage, was also made. They have been loved since ancient times, as evidenced by their inclusion in the Manyoshu (The Anthology of Myriad Leaves). They are widely distributed in Honshu, Shikoku, and Kyushu, and in Tokyo, they live in the Okutama area where Mt.</span></p>
<p> In the &#8220;Birds, Animals, and Caricatures,&#8221; a collection of caricatures of birds and animals dating back about 800 years, frogs are personified along with rabbits and monkeys, and are depicted playing in the water and wrestling.</p>
<p><span class="strongInContent"> In one of the pictures of sumo wrestling, a frog, probably a tree frog, throws a rabbit to the ground, indicating that frogs have been loved by people since ancient times.</span></p>
<p> Japan is long from north to south, and the climates of Hokkaido and Okinawa are very different. Naturally, the ecology of the frogs living there is also different.</p>
<div data-friday-ad-slot="AD_inArticle"></div>
<p><span class="strongInContent"> The ichneumon frogs found on Ishigaki and Iriomote Islands in Okinawa Prefecture raise their young as a couple. They lay their eggs in puddles of water in tree hollows. The father frogs keep their wet bellies moist and watch for the arrival of natural enemies. Since there is no food such as algae, the mother frog feeds unfertilized eggs.</span></p>
<p><span class="strongInContent"> Ordinary tadpoles have their mouths facing downward to feed on algae on the bottom of the water, but Eiffinger&#8217;s tadpoles have their mouths facing forward so that they can easily suck in unfertilized eggs. If you look closely, you can see the face of the tadpole.</span></p>
<div data-friday-nextpage-lead=" The &quot;2 of 54&quot; that Mr. Sakono has yet to meet."></div>
<h3><span class="strongInContent">The journey to find frogs continues!</span></h3>
<p> Genetic analysis is progressing, new species are being discovered, and as already mentioned, the number of species has increased to 54. So far, Sakono has encountered 52 species of frogs.</p>
<p><span class="strongInContent"> Two species, the Sado Island frog and the Gotoh tag frog, I haven&#8217;t met yet,&#8221; he said. As their names suggest, they are distributed on Sado Island in Niigata Prefecture and on the Goto Islands in Nagasaki Prefecture. Sado frogs live in the rice paddies of Sado Island and are often eaten by crested ibis. Sado is a pleasant environment for frogs because of its satoyama environment for ibis breeding.</span></p>
<p><span class="strongInContent"> In the Goto Islands of Nagasaki Prefecture, the Goto and Tagotago frogs seem to be distributed on each island.</span><span class="strongInContent"> I have visited all 47 prefectures, but there are many islands in Japan, and there are likely to be new species for each island and region, so my journey in search of frogs is likely to continue.</span></p>
<div data-friday-ad-slot="AD_inArticle"></div>
<p> If it is a species that lives in the rice paddies, he says, it is easy to raise them from tadpoles to frogs. If you fill a bucket with rice paddy mud and water, you can witness their dramatic metamorphosis to adulthood. However, there is a caveat.</p>
<div data-friday-ad-slot="AD_inArticle"></div>
<p><span class="strongInContent"> The mud contains plankton such as Daphnia magna, and the mud itself is a mass of organic matter, which the tadpoles feed on as they grow larger. The metamorphosis of the tadpoles is very impressive. If they are tree frogs, they climb out of the bucket using suckers on their limbs.</span></p>
<p><span class="strongInContent"> But do not move the area too far. It could lead to the adult frogs disrupting the ecosystem of that remote area. There have been cases, for example, of more than one species of tree frog being found on Izu Oshima Island, where they are not supposed to be.&#8221;</span></p>
<p> There are many different species of frogs, including those that live in rice paddies, on trees, and along mountain streams. Even in Honshu, some species breed in winter. This weekend, why don&#8217;t you look for these mysterious creatures with dull eyes?</p>
<div data-friday-nextpage-lead=" The frog illustrations by Mr. Sakono are full of love."></div>
<figure id="attachment_458908" aria-describedby="caption-attachment-458908" style="width: 3497px" class="wp-caption alignnone"><a href="#" data-ident_hash="4e1db78b"><img src="https://res.cloudinary.com/fridaydigital/image/private/t_article_image/wpmedia/2026/02/bab3e5762d11d1ac0bd6c38dbe57ac8b.jpg" alt=""></a><figcaption id="caption-attachment-458908" class="wp-caption-text">Tagogawa frog. Found throughout Japan except Hokkaido and parts of Honshu (from &#8220;48 Frogs of Japan: An Eccentric Illustrated Guide&#8221; ©Sakono Takahiro 2026).</figcaption></figure>
<div data-friday-ad-slot="AD_inArticle"></div>
<figure id="attachment_458910" aria-describedby="caption-attachment-458910" style="width: 3497px" class="wp-caption alignnone"><a href="#" data-ident_hash="43bba864"><img src="https://res.cloudinary.com/fridaydigital/image/private/t_article_image/wpmedia/2026/02/d018b5ab5e1f483a45c4dcc1703f187e.jpg" alt=""></a><figcaption id="caption-attachment-458910" class="wp-caption-text"> Nevatago frog. Until recently, it was thought to be a tagomorph (from &#8220;48 Frogs of Japan&#8221; ©Sakono Takahiro 2026).</figcaption></figure>

<figure id="attachment_458911" aria-describedby="caption-attachment-458911" style="width: 3497px" class="wp-caption alignnone"><a href="#" data-ident_hash="083fd76a"><img src="https://res.cloudinary.com/fridaydigital/image/private/t_article_image/wpmedia/2026/02/402b57fc51407643aa04ff535eeca7a8.jpg" alt=""></a><figcaption id="caption-attachment-458911" class="wp-caption-text"> Kajika frog. Their beautiful calls led to a boom in breeding during the Edo period (from &#8220;48 Frogs of Japan: A Prejudiced Illustrated Guide&#8221; ©Sakono Takahiro 2026).</figcaption></figure>
<div data-friday-ad-slot="AD_inArticle"></div>
<figure id="attachment_458912" aria-describedby="caption-attachment-458912" style="width: 3497px" class="wp-caption alignnone"><a href="#" data-ident_hash="b81fff96"><img src="https://res.cloudinary.com/fridaydigital/image/private/t_article_image/wpmedia/2026/02/89f3ee7d8aecd15f9d94f172414b2d27.jpg" alt=""></a><figcaption id="caption-attachment-458912" class="wp-caption-text"> Eiffinger&#8217;s frog. Found on Ishigaki and Iriomote Islands. They lay their eggs in puddles in tree hollows and raise their young as a couple.</figcaption></figure>

<figure id="attachment_458913" aria-describedby="caption-attachment-458913" style="width: 3497px" class="wp-caption alignnone"><a href="#" data-ident_hash="2b7693cb"><img src="https://res.cloudinary.com/fridaydigital/image/private/t_article_image/wpmedia/2026/02/d1b14d26cc3fb2709f93da76693b6870.jpg" alt=""></a><figcaption id="caption-attachment-458913" class="wp-caption-text"> Sado frog. It lives on Sado Island. One of two species that Sakono has yet to meet. Commonly seen in the rice paddies of Sado Island. (From &#8220;48 Frogs of Japan: An Eclectic Illustrated Guide&#8221; ©Sakono Takahiro 2026)</figcaption></figure>
<figure id="attachment_458920" aria-describedby="caption-attachment-458920" style="width: 365px" class="wp-caption alignnone"><a href="#" data-ident_hash="0d0c47c2"><img src="https://res.cloudinary.com/fridaydigital/image/private/t_article_image/wpmedia/2026/02/1bfcce379b0b5a5755a60613bee98134.jpg" alt=""></a><figcaption id="caption-attachment-458920" class="wp-caption-text"> 48 species of frogs are introduced with photographs and lovingly handwritten illustrations. The new edition also includes six newly discovered species.</figcaption></figure>
<div class="expapp-no-provided-scope expapp-no-provided-scope-line-only-start"></div>
<p><a href="https://amzn.to/4cdQwgu"> 48 Frogs of Japan: Sakono-kun&#8217;s Field Notes,&#8221; by Takahiro Sakono, published by Kawade Shobo Shinsha, Tokyo University.</a></p>
<div class="expapp-no-provided-scope expapp-no-provided-scope-end"></div>


 Daisuke Iwasaki

 There are 54 species of frogs in Japan alone. Takahiro Sakono, who traveled all over Japan to meet all of them, has published a new edition of "48 Frogs of Japan: An Eclectic Illustrated Book," which was first published in 2008. We asked him about his overflowing love for frogs.

Some frogs croak &#8220;wan-wan, can-can&#8221;&#8230; The author of &#8220;The Illustrated Book&#8221; talks about his love for frogs, of which there are 54 species in Japan alone.

Some frogs croak “wan-wan, can-can”… The author of “The Illustrated Book” talks about his love for frogs, of which there are 54 species in Japan alone.

Access Ranking