YOKA SHICHIRIN++

SHICHIRIN++: an all-stainless shichirin that rethinks the basic structure

YOKA's SHICHIRIN++ is a tabletop charcoal cooker built entirely from stainless steel. It works as a shichirin for grilling and for pot cooking, and it can also be used as a fire pit. This shipment is the 6th production lot, and the structure is patent pending.

In programming, "++" is the operator that adds one to the variable on its left. Each time the loop runs, the value goes up by one. The name SHICHIRIN++ carries that idea: the shichirin is not treated as finished in a single version, but as a tool that keeps being refined.

The shichirin has been in use since the Edo period, and its basic structure has changed little in that time. SHICHIRIN++ makes five changes to that conventional structure: removing the air holes, adding a lid, putting the charcoal in a basket, switching the material to stainless steel, and making the grate two-tiered. YOKA describes this approach as "the first update in 400 years."

Rather than simply swapping the material of a shichirin for stainless steel, SHICHIRIN++ connects lighting, cooking, extinguishing, storing the charcoal and relighting it next time inside a single tool. The shell with no side air holes, the core that holds the charcoal, the lid used to put the fire out, the charcoal starter used for lighting and the two-tier grate each play a part in that sequence.

No air holes: air is drawn in from the top

There are no air holes on the sides or the base, as there are on a typical shichirin; only the top is open. The charcoal sits in a basket called the core, and a space is kept between the core and the outer shell. Air taken in from the top travels down toward the base and burns the charcoal.

Because there are no openings on the sides or the base, ash is unlikely to spill out even when the unit is used on a table. The air holes of a conventional shichirin are also used to control the heat, but they are a route for ash — sometimes ash carrying sparks — to escape. The extra places to clean and the effect on the strength of the body are also reasons SHICHIRIN++ does away with the air holes.

Air holes let you change the airflow to adjust the heat, but for anyone not used to handling charcoal, that adjustment can make things harder rather than easier. SHICHIRIN++ instead uses its own structure that draws air in at the top and circulates it to the base, and its combustion efficiency is calculated so that it delivers heat comparable to a typical shichirin without side or bottom air holes.

Put the charcoal out by closing the lid

Closing the included lid restricts the oxygen supply inside and smothers the fire. There is no need to move burning charcoal to a separate extinguishing pot; the charcoal can be put out inside SHICHIRIN++ while still lit.

Because no step involves moving charcoal outside the shichirin, the situations where sparks fly during extinguishing are greatly reduced. With the lid closed, the body becomes a capsule, so fire and charcoal are unlikely to scatter. Engaging the lock keeps the lid from coming off even if the unit is knocked over.

After the fire is out, the charcoal can be stored fully sealed, so SHICHIRIN++ itself doubles as a charcoal storage case. There is no need to take the leftover charcoal out and move it to another container, and that partly burned charcoal can be reused as it is next time.

Note, however, that the body does not cool down immediately once the lid is closed and the fire is out. It stays hot for about an hour afterwards, so take the temperature into account when moving or packing it away.

Lighting, extinguishing and relighting, all around the body

SHICHIRIN++ combines the core that holds the charcoal with the included charcoal starter, so that lighting the fire, putting it out and relighting it next time can all be done around the body itself.

To relight, lift out the core holding the partly burned charcoal from the previous session, place a firelighter underneath and use the charcoal starter. You can light the fire without transferring the charcoal to a separate chimney starter and without taking lit charcoal outside the shichirin.

After use, close the lid to put the charcoal out and store it as it is. Next time, the remaining charcoal can be lit again together with the core. Not having to move charcoal into another container at every stage — lighting, extinguishing, storing and relighting — is a defining feature of the way SHICHIRIN++ is built.

All stainless steel, washable with water and detergent

The body is made entirely of stainless steel. A typical diatomaceous earth shichirin is vulnerable to water and not suited to being washed, but SHICHIRIN++ can be washed with water and detergent in the same way as a pot or a dish.

Along with the ash left after using charcoal, the oil that drips from grilled food can also be washed away, so dirt and burnt residue do not build up. For a cooking tool used repeatedly, being able to wash the body after use is a significant difference from a conventional diatomaceous earth shichirin.

It is also not a material that cracks easily under impact, as diatomaceous earth does. That makes it easy to handle as a camping tool intended to be carried, and the structure is designed with taking a tabletop shichirin out into the field in mind.

Two grate tiers to separate heat levels and cooking space

The grate can be used on two levels. The basic idea is to treat the upper tier, closer to the charcoal, as high heat, and the lower tier, further away, as medium heat. Beyond changing the height at which food sits to suit how it should cook, you can also use both levels at once.

You can keep a pot or small cooking vessel on the upper tier while continuing to grill on the lower tier. You could, for example, make ajillo on the upper tier while toasting bread on the lower one, or warm sake in a water bath on the upper tier while grilling yakitori below.

For skewered food, the structure gives the skewers somewhere to sit, and charcoal can be added through the hole in the centre of the lower tier. It handles cooking over a wood fire as well as over charcoal.

Placing the upper grate in the lower position leaves a slight step but makes the top surface close to flat, and it can be used that way. This is also the arrangement for storage, with each part packed inside the body.

Besides the original grate, commercially available 24 cm grates can also be used. For dishes where cleaning the grate afterwards is a chore — meat in a marinade, for example — a commercial grate can be treated as disposable. If you do, choose a grate with a domed, raised shape.

Heat during tabletop use, and notes for balconies and gardens

There is an air layer between the outer stainless shell and the core that holds the charcoal, so the heat of the charcoal does not pass straight through to the outside or the base. Even so, the base can become hot during long sessions. For tabletop use, place the included lid underneath SHICHIRIN++.

Because there are no air holes on the sides or the base, ash is unlikely to scatter around when you have a barbecue on a balcony or in a garden, and after use you can close the lid and move straight to extinguishing. That said, using charcoal does produce smoke. In residential areas, consideration for neighbours is necessary, and in apartment buildings and similar housing, please follow the rules of the building.

Improvements made lot by lot

SHICHIRIN++ has been refined structurally from one production lot to the next. From the 3rd lot, delivered in September 2025, the shell changed from two parts welded together to a single moulded piece. The tabs that hold the grate are riveted rather than welded, reducing the risk of deformation from welding heat.

From the 5th lot, the core was also redesigned. The stopper that holds the charcoal starter in place changed from a welded ball to a shape in which the leg itself is bent to serve as the stopper. Removing a separately welded part makes the core more robust.

From crowdfunding to general release

SHICHIRIN++ ran a crowdfunding campaign on Kibidango, receiving support from 1,880 backers and more than 32 million yen in total by February 2025. After the campaign ended it moved to general release, and production has continued through successive refinements to the current 6th lot.

It has also been covered by Japanese outdoor media including CAMP HACK, BE-PAL, Outdoor Gearzine, Happy Camper, CAMPLOG GEAR and hinata.

Packed size and what is included

In use the unit measures 245 × 245 × 230 mm high. Packed, the height comes down to 197 mm, with the parts stowed inside the 245 mm square body. What is included: the shell that forms the body, the lid, the core, the charcoal starter and the legs. The weight including all of these is approximately 2.9 kg.

Specifications