築地の王様 Gokujo Bluefin Tuna Chutoro 400g (極上 本まぐろ 中トロ; “gokujo” is part of the product name) is bluefin tuna (honmaguro) chutoro (medium-fatty tuna belly) sold on Rakuten Ichiba by 株式会社Food Stream Japan of Koto City, Tokyo, through its shop “うに カニ まぐろなら築地の王様”. Its origin / place of production is shown as 大西洋・地中海マルタ (Atlantic Ocean, Mediterranean Sea, Malta), and it arrives frozen as two saku (rectangular blocks cut for slicing) of about 200g each. The ingredients are labeled “養殖本まぐろ” (farmed bluefin tuna) on the Rakuten listing, while the Amazon listing says “蓄養本マグロ（クロマグロ）” (stock-farmed bluefin tuna, kuromaguro), so the two labels do not match. We have organized what the Rakuten listing and reviews say into five points: contents, shelf life, ingredients, gift use and reviews. The features confirmed on the listing are three: delivery as two saku of about 200g each, a best-before date of 7 days frozen from the shipping date, and support for noshi (gift wrapping label).
At a Glance
Key points
- Two saku of about 200g each, 400g in total. Of the 5 tuna, sashimi and seafood bowl products featured on Ochinity (as of October 21, 2026), 2 are bluefin tuna chutoro. Compared with the other one, Bluefin Tuna Chutoro Saku 500g (“wakeari”, meaning imperfect/irregular, sold at a discount; farmed), this product is a regular item, not wakeari
- Arrives frozen; the best-before date is 7 days frozen from the shipping date. The listing advises keeping it frozen at −18°C or below and avoiding refreezing
- Noshi can be added. The listing says noshi can be added to gifts such as ochugen (mid-year gift), oseibo (year-end gift), Mother’s Day and Father’s Day
- Rakuten rating: 4.45 (137 reviews). Viewed October 21, 2026. Most of the 76 reviews we read were posted between 2011 and 2014
Watch out for
- At 400g in total, this is the smallest amount among the 5 tuna, sashimi and seafood bowl products featured on Ochinity (as of October 21, 2026)
- The ingredient labeling differs between Rakuten (“養殖本まぐろ”, farmed bluefin tuna) and Amazon (“蓄養本マグロ（クロマグロ）”, stock-farmed bluefin tuna, kuromaguro). This article follows the labeling on Rakuten, where it is sold
- Shelf life after thawing, allergen labeling and the manufacturer are not stated on the listing and are Not confirmed
Suits: Someone who wants to give bluefin tuna chutoro saku with noshi attached, or who wants chutoro sold as a regular item rather than wakeari
The comparison covers the 5 tuna, sashimi and seafood bowl products featured on Ochinity (as of October 21, 2026). Each value is from the information-as-of date of its own article and may differ from the current details. Features are from the Rakuten Ichiba listing (viewed October 21, 2026). The rating is as shown on Rakuten (viewed October 21, 2026) and may not represent the product’s current condition.
Compared with 5 Tuna, Sashimi and Seafood Bowl Products
The 5 tuna, sashimi and seafood bowl products featured on Ochinity (as of October 21, 2026). Each value is from the information-as-of date of its own article and may differ from the current details. Ratings are as shown on Rakuten and may not represent the product’s current condition (for this article’s product, we read 76 reviews). The fewer the reviews, the more easily the figure moves. The table is in the Japanese syllabary (gojūon) order of the product names, not in order of rating or amount.
| Product | Total amount | Servings guideAs written by the shop | Rakuten rating |
|---|---|---|---|
| 魚耕 Wild Red Shrimp, Head-On, 2kgFrozen | 2000g | Not confirmed | 4.56267 reviews |
| 築地の王様 Gokujo Bluefin Tuna Chutoro 400gThis article; frozen; chutoro | 400gAbout 200g × 2 saku | Not confirmed | 4.45137 reviews |
| Bluefin Tuna Chutoro Saku 500g, Wakeari, FarmedFrozen; chutoro | 500g | 5 to 6 servings | 4.57381 reviews |
| Masuyone Echizen Amaebi without Roe 500gFrozen | 500g | 2-4 servings | 4.67,733 reviews |
| Masuyone Echizen Sweet Shrimp with Roe 500gFrozen | 500g | Not confirmed | 4.626,803 reviews |
Click a product name to go to that product’s article.
- Of the 5 tuna, sashimi and seafood bowl products featured on Ochinity (as of October 21, 2026), the bluefin tuna chutoro products are this one and Bluefin Tuna Chutoro Saku 500g (wakeari, farmed). This product is a regular item, not wakeari, and its total amount is 100g less
- The total of 400g is the smallest of the 5, and the Rakuten rating of 4.45 (137 reviews) is also the lowest figure of the 5 (the other 4 range from 4.56 to 4.62)
Basic Information
- Product name
- 築地の王様 Gokujo Bluefin Tuna Chutoro 400g
- Contents
- Saku of about 200g × 2 (the number of servings is Not confirmed)
- Ingredients
- “養殖本まぐろ” (farmed bluefin tuna) (as labeled on Rakuten)
- Origin / place of production
- 大西洋・地中海マルタ (Atlantic Ocean, Mediterranean Sea, Malta)
- Storage
- Keep frozen at −18°C or below; the listing says the best-before date is 7 days frozen from the shipping date
- Thawing
- The shop says it provides a thawing manual (the steps themselves are Not confirmed)
- Allergen labeling
- Not confirmed
- Noshi / gifts
- Noshi available (wrapping and message cards are Not confirmed)
This list transcribes what is stated on the listing. However, the “Not confirmed” labels and any notes we add are our own.
The listing does not give allergen labeling. If you have allergies, be sure to ask the shop before you buy, or check the label on the item when it arrives (reference: Consumer Affairs Agency, Japan, “About Allergen Labeling”, accessed October 21, 2026).
See the transcribed details, sources and “Not confirmed” items (16 items)
This list transcribes what is stated on the listing. However, the “Not confirmed” labels and any notes we add are our own.
- Product name
- 築地の王様 Gokujo Bluefin Tuna Chutoro 400gThe product name shown on the Rakuten listing is a long string with many search terms. Here it is given from the product-name field of the product description (極上本まぐろ中トロ400g) and the shop name.
- Contents
- The listing says it arrives as two saku of about 200g each (400g in total). The number of servings is not stated and is Not confirmedSource: product description on the Rakuten Ichiba listing (accessed October 21, 2026)
- Options
- There are no option fields; it comes in one type, 400g (about 200g × 2 saku)Source: Rakuten Ichiba listing (accessed October 21, 2026)
- Cut
- ChutoroSource: product description on the Rakuten Ichiba listing
- Ingredients
- Labeled “養殖本まぐろ” (farmed bluefin tuna). The Amazon listing (築地の王様 マグロ 極上 本まぐろ 中トロ 400g) says “蓄養本マグロ（クロマグロ）” (stock-farmed bluefin tuna, kuromaguro), so the labeling differs. This article follows the labeling on Rakuten, where it is soldSource: product description on the Rakuten Ichiba listing and the Amazon listing (both accessed October 21, 2026)
- Allergen labeling
- Not confirmed (we could not find it on either the Rakuten or the Amazon listing)
- Storage method
- Keep frozen at −18°C or below. The listing advises avoiding refreezingSource: product description on the Rakuten Ichiba listing
- Best-before date
- 7 days frozen from the shipping dateSource: product description on the Rakuten Ichiba listing
- Thawing method
- An image on the listing says the shop provides an easy thawing manual (かんたん解凍マニュアル) that is easy to follow even for people trying frozen tuna for the first time. The thawing steps themselves are not written on the listing and are Not confirmedSource: images in the description on the Rakuten Ichiba listing (accessed October 21, 2026)
- After opening
- The listing says that, depending on the part, some skin, bones or dark meat (chiai) may be attached, and advises removing them before eating. It also says the surface has cutting residue (kiriko) from when the saku were cut. Shelf life after thawing is not stated and is Not confirmedSource: product description on the Rakuten Ichiba listing (notes)
- Origin of ingredients
- The origin / place of production field says 大西洋・地中海マルタ (Atlantic Ocean, Mediterranean Sea, Malta)Source: product description on the Rakuten Ichiba listing
- Place of processing
- Not confirmed. The product description says the saku are cut at the Tsukiji market (築地市場)Source: product description on the Rakuten Ichiba listing (notes)
- Condition / how to eat (cooking needed?)
- Arrives as frozen saku. We could not find any guidance on whether it needs cooking or can be eaten raw (the product name shown on the Rakuten listing includes the words 刺身 (sashimi), 寿司 (sushi) and 海鮮丼 (seafood bowl))Source: Rakuten Ichiba listing (accessed October 21, 2026)
- Delivery
- Arrives frozen. The name of the delivery method and the number of days until shipping are Not confirmedSource: Rakuten Ichiba listing (accessed October 21, 2026)
- Noshi / gifts
- Noshi can be added. The listing says noshi can be added to gifts such as ochugen, oseibo, Mother’s Day and Father’s Day. Packaging such as a gift box, and message cards, are not stated on the listing and are Not confirmedSource: product description and gift section of the Rakuten Ichiba listing (accessed October 21, 2026)
- Manufacturer
- Not confirmed (we could not find the manufacturer or processor stated)
- Shop
- うに カニ まぐろなら築地の王様 (operating company: 株式会社Food Stream Japan, Koto City, Tokyo)Source: company profile on Rakuten Ichiba (accessed October 21, 2026)
Prices are not listed here because they change. Please check the current price and stock availability at the link above.
What Public Reviews Say
We organized the Rakuten Ichiba product reviews by theme. The rating figures reflect the time of viewing and will change. The summary below covers only the reviews we read and may not reflect the product’s current condition.
| Site | Rating | Number of Reviews | Date Accessed |
|---|---|---|---|
| Rakuten customer reviews (product page) | 4.45 / 5 | 137 | October 21, 2026 |
Rating breakdown: 5★ 91 / 4★ 30 / 3★ 7 / 2★ 4 / 1★ 5 (as shown on Rakuten Ichiba, viewed October 21, 2026)
What we read: the first 60 reviews in Rakuten’s default order (posted January 2011 to May 2026; latest May 2026), plus all 5 reviews rated 1★ (posted January 2013 to February 2021), all 4 rated 2★ (posted June 2012 to March 2025) and all 7 rated 3★ (posted November 2012 to April 2016), 76 in total. These are trends within what we read and may not reflect the product’s current condition.
Most of the 76 reviews we read were posted between 2011 and 2014; only 4 were posted in or after October 2024 (3 from the default order and 1 rated 2★). The trends below are mainly based on posts from more than 10 years ago and may not apply as they are to the current product. The counts are approximate, based on reading the review texts, and do not include posts only about delivery or the shop’s service.
What Reviewers Praise
Thawing as instructed worked well (about 22 of 60)
About 22 of the 60 reviews in the default order said that thawing it as the enclosed thawing instructions describe worked well, or that the instructions were easy to understand. Of these, 2 were posted in or after October 2024.
Fatty like otoro and melts in the mouth (about 12)
About 12 of the 60 reviews in the default order said it was so fatty that they thought it was otoro (the fattiest tuna belly) even though it was chutoro, or that it melted in the mouth. All were posted between 2011 and 2014.
Well received as a gift (about 14)
About 14 of the 60 reviews in the default order said they sent it as an oseibo, ochugen, Father’s Day or Mother’s Day gift, or as a kaiki-iwai (recovery celebration) gift, and that the recipient was pleased. All were posted between 2011 and 2014.
Repeat purchases; used for sushi or rice bowls (about 14)
Among the 60 reviews in the default order, about 14 said they buy it repeatedly, for example every year for the New Year, and about 6 said they ate it as sushi or on rice bowls (as described by the reviewers).
Source: Rakuten customer reviews (accessed October 21, 2026)
What Reviewers Note
Lots of sinew; quality varies between saku (9)
9 reviews said one of the two saku had a lot of sinew (suji), or that the quality was uneven: 2 rated 1★, 2 rated 2★, 2 rated 3★ and 3 from the default order. They were posted between 2012 and 2016.
How to check: the form of the saku that arrive, and the shop’s note that skin, bones or dark meat may be attached, are in the “Contents” and “After opening” rows of the detailed list in the “Basic Information” section of this article.
Failed thawing / freezer burn (3)
3 reviews said the thawing failed and it turned dry, that it smelled fishy, or that it had bad freezer burn after thawing: 1 rated 1★ (2020), 1 rated 2★ (2018) and 1 rated 5★ from the default order (2026).
How to check: the shop’s guidance on thawing and storage is in the “Thawing method” and “Storage method” rows of the detailed list in the “Basic Information” section of this article.
Being farmed / not good value (2)
There were 2 such reviews: a 1★ review (2021) saying the reviewer had thought it was wild but it was farmed, and a 2★ review (2025) saying it did not feel like good value.
How to check: the ingredient labeling is in the “Ingredients” row of the “Basic Information” section of this article.
Source: Rakuten customer reviews (accessed October 21, 2026)
Summary: Is This the One for You?
Deciding factor: You want to give it with noshi attached, and you want bluefin tuna chutoro saku that is a regular item, not wakeari. If these two are your conditions, of the 2 bluefin tuna chutoro products featured on Ochinity (as of October 21, 2026), this is the one that meets both (weak point: the total amount is 400g, the smallest among the 5 tuna, sashimi and seafood bowl products).
- The listing says noshi can be added to gifts such as ochugen, oseibo, Mother’s Day and Father’s Day
- It arrives as two saku of about 200g each, and the best-before date is 7 days frozen from the shipping date
- The Rakuten rating is 4.45/5 (137 reviews). Among the 76 reviews we read, many said thawing as instructed worked well (about 22 of 60) or that it was well received as a gift (about 14), while 9 mentioned that the amount of sinew varied from saku to saku. Most of the reviews were posted between 2011 and 2014
Other options: If you want more for home use rather than as a gift, see Bluefin Tuna Chutoro Saku 500g, Wakeari, Farmed (500g; 5 to 6 servings as written by the shop); if you prefer sweet shrimp (amaebi), see Masuyone Echizen Amaebi without Roe 500g.
This section is based on the Rakuten Ichiba listing and Rakuten customer reviews (accessed October 21, 2026), and on the articles for the 5 tuna, sashimi and seafood bowl products featured on Ochinity (as of October 21, 2026). These are trends within the reviews we read and may not reflect the product’s current condition.
Prices, stock, shipping fees, and delivery dates are subject to change. The information in this article was gathered on October 21, 2026. Please be sure to check the listing at the link before purchasing.
This article contains affiliate links (advertising). Editorial Policy
This article summarizes information publicly available on retail sites and review sites. Product details such as amount, storage method, and ingredients are subject to change. Please check the seller’s listing for the most current information.
Assessments of taste and quality are summarized from third-party posts with sources cited, and do not represent Ochinity’s own evaluation. Our editorial process is described in the Editorial Policy.
Information as of: October 21, 2026 / Sources: Rakuten Ichiba “うに カニ まぐろなら築地の王様” product page and company profile, the Amazon product page, Rakuten customer reviews, Consumer Affairs Agency “About Allergen Labeling”
