Welcome to Marusho

Marusho Co., Ltd is a shiitake mushroom trading company that operates in Fujieda-shi, Shizuoka. We purchase shiitake mushrooms from farmers and local producers nationwide before our skilled staffs choose which mushrooms to sell at the main factory to flexibly comply with the customer’s request. We offer delicious donko shiitake mushrooms while cherishing the producer’s feelings conveyed through the mushroom’s taste and their effort to make them taste delicious, as well as prioritizing product safety over everything else.

Log Cultivation and Mushroom Bed Cultivation

There are 2 types of mushroom cultivations, log cultivation and mushroom bed cultivation. Log cultivation is a cultivation method of inoculating oak or beech tree logs ranged from 20 to 25 years with shiitake fungi, and allows the fungi to spread and grow in the forest. It will take approximately half a year to 2 years to propagate shiitake fungi (The process of growing the shiitake fungi on the tree logs is called “hodaka”). The mushrooms will have thick flesh, a stronger aroma, and deliciously chewy texture. Mushroom bed cultivation is a cultivation method of inoculating the bed area built from sawdust mixed with nutrient supplements such as water and rice bran with shiitake fungi. It will take approximately 3 months for the mushrooms to grow after spreading them inside the facilities with air conditioning units. The mushrooms are distinguishable by their constant shape and color.

Mushroom Bed Cultivation

Log Cultivation

About Log Cultivation
(Shiitake Mushroom Log)

The high ground area is a very harsh environment due to its temperature difference between day and night, resulting in the mushrooms having a tasty flavor. The temperature exceeds 30 degrees during the daytime, causing the mushroom to dry properly. When the temperature cools down during the night, the mushrooms absorb moisture from the air, allowing them to grow. The shiitake mushrooms that survive these extreme conditions will have a chewy, tender texture, and a dynamic flavor close to the shiitake mushrooms found in the wild.

Cultivation Time

Logging from October to March.


Inoculation from November to April.

After inoculation - Karifuse (Covering wood logs with vinyl sheet and control the moisture and temperature condition) / Honfuse (Metabolize the logs by giving them dry or wet condition) around April. Growing / Harvest Drying

To all producers and farmers

Which shiitake mushroom is delicious?

About “donko shiitake mushroom”

The highest grade of shiitake that is best identified by its small, firmly closed cap.

About “koko / koshin shiitake mushroom”

The mushroom cap of “donko shiitake” will open as the mushroom grows. Shiitake with a partially open cap is called “koko shiitake”, while shiitake with a wide-open cap is called “koshin shiitake”.

Types of Shiitake Mushroom

Tenpaku Donko

The highest quality grade of shiitake mushroom. Back then, the mushroom was regarded as the first prize for winning a competition in ancient China.

Chabana Donko

Best identified by its thick flesh and the flower pattern on its cap. Both tenpaku donko and chabana donko are carefully cultivated during winter. They have natural cracks in their caps due to low temperature.


Donko shiitake has a round shape and a large, thick cap. It is pleasantly chewy and famous for or its rich, meaty flavor. The mushroom is ideal for boiled foods or fried foods to taste its chewy texture.


Yori shiitake is thinner than donko shiitake, and it has a fully open cap. Compared to donko shiitake, yori shiitake has stronger aroma. This mushroom is pleasant to look at due to its curved shape, and it is generally used to make osechi ryori (Japanese New Year’s food).


Identified by its thin cap, the mushroom is harvested after the cap has opened. True to its name (The kanji consists of ”香” which means smell), koshin shiitake has the strongest aroma amongst shiitake mushrooms. The mushroom is usually chopped into pieces and used for soup and takikomi gohan (Japanese mixed rice).

The Secret of the Dried Shiitake Mushroom’s Tasty Flavor

Drying the shiitake mushroom will break the cells and cause the enzyme to work, enhancing the flavor in the process. Soaking the mushroom in water before heating it allows the enzyme to become active, causing an approximately tenfold increase of a component called guanylic acid in its savory flavor. Guanylic acid is one of "three great flavor components" of Japanese cuisine. Its deliciousness is the main reason why people still eat dried shiitake mushroom as a traditional food since 1000 years ago.

How to Choose Dried Shiitake Mushroom

The key to harvesting the mushroom from the tree log is to look for a mushroom with a thick and short stem. The mushroom is said to have thick flesh and tasty flavor. A cracked cap shiitake mushroom is called "hana donko" (flower donko) due to its resemblance to a flower. Hana donko is even more delicious and expensive than normal donko shiitake. Please be sure to choose the bag of mushrooms which contains lots of shiitake mushrooms with cracked caps.

How to Choose Shiitake Mushroom in the Wild

The newly grown mushroom has pale, yellowish white gills underneath the cap. However, the yellow tinge on the gills will become darker, and the cap will develop dark spots as the mushroom matures. Also, the mushroom with dark spots contains lots of moisture and has soft texture, resulting in shorter shelf life.

Product Processing / Quality Control

We are aiming to establish an unrelenting quality control system by thoroughly conducting bacteriological examinations, radiological examinations, residual pesticide tests, and foreign matter examinations.

Our Main Factory’s Working Process

Purchase shiitake mushroom from farmers markets nationwide


Sorting by size based on similar standard

Raw materials → Sorting

Machines have not been able to conduct this process since a long time ago. This is the most important process and it is necessary to distinguish the products by our standards. Therefore, we have our skilled staffs do the whole process. If there is a mistake, we have no choice but to redo the whole process, and foreign matters would even show up during the process. Also, it is possible to find metal pieces within the products by using a metal detector during the examination.

Slicing Process

Slicing process concluded

Metal detector


Final check

During the final check, we will also conduct a further inspection using a high precision metal detector.

Bagging the Mushroom Slices

We could also change the size of the mushroom slice according to the customer requests.

Bagging the Mushroom for Home Use

Sliced mushrooms used for cooking are available as well.

Xiamen Factory, China (Xiamen Marusho)

Our company has been purchasing Chinese shiitake mushrooms in the said land for about 20 years. In 2004, we established a Chinese factory in Tong’an District, Xiamen Prefecture, Fujian Province, China, and export shiitake mushrooms to Japan and around the world. Our corporate motto is “Provide the customers with safe and healthy foods.” We manage a comprehensive list of processes, from raw material procurement to processing and sales. Our company adopts Japanese production technology, and we manage to operate under its strict quality control system. For this reason, we acquired ISO 22000 HPCCP at our factory in China. It is also possible to produce the products according to customer's needs. We are very proud that we have achieved the AAA credit rating.

Xiamen Marusho Laboratory

It is possible to measure the amount of moisture, distribution, and SO2.

Metal Detector

We deliver all the products, both the unsliced mushrooms and the sliced mushrooms after inspecting them using a metal detector at our China factory. We conduct quality control before shipping our products to ensure customer safety.

Xiamen Factory, China (Appearance)

Our company has an area of 10,000m² in Xiamen, 1,500m² of which is our company house while 5,000m² is the factory. The company’s annual production volume is 1,000 tons. We mainly export our products to Japan, the United States, Europe, Southeast Asia, etc. Currently, we have ISO 22000 HPCCP at our factory in China.

Xiamen Product Selection

In Xiamen Marusho, there are local staffs who received training in Japan. We purchase safe materials from the local producers nationwide before our skilled staffs select and sort them according to our company’s standard. We aim to produce only high-quality products.

Company Profile

Name of company

Marusho Co., Ltd


Masao Suzuki


P.O. Box 65, 738-1 Kori, Fujieda-shi, Shizuoka 426-0016

Contact Us

Please make your inquiry by telephone, fax, or email address.

Marusho Co., Ltd

738-1 Kori, Fujieda-shi, Shizuoka 426-0016
Tel: 054-641-1388
Fax: 054-644-5118

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