米蔵証券 Kome Reserves

1 · The instrument already existed

In 1730 the Tokugawa shogunate authorised trading in rice bills — 米切手, kome kitte — at Dōjima in Osaka. A domain warehoused its tax rice, the warehouse issued a bill naming the stored lot, and the bill traded. Buyers took the paper; the rice stayed put. Dōjima is widely recognised as the world's first organised futures exchange, and the underlying was a warehouse receipt for grain.

Kome Reserves is not a new financial instrument. It is that instrument with a public settlement layer and a grade floor. The warehouse still holds the rice, the receipt still moves faster than the cargo, and the price still travels faster than both — the Dōjima price was relayed across hundreds of kilometres by flag signal precisely because the information mattered more than the sack.

Nothing in the third column is an invention. The chain replaces the courier and the clearing house. It does not replace the receipt, and it cannot replace the warehouse.

2 · What is in the vaults

8 vaults across 8 prefectures, 8 varieties, 40 lots. Total 42,000 俵 (2,520.0 tonnes, 16,800 石, 2,520,000 kg). The anchor is 魚沼 Uonuma, Niigata — Minamiuonuma, Koshihikari, 11,400 俵 across 9 lots. Sole Niigata district holding Special A in 2023, 2024 and 2025.

3 · The admission rule

The Japan Grain Inspection Association publishes an annual taste ranking, scoring each district's rice against a blended Koshihikari control. The bands, descending: 特A · A · A′ · B · B′. Kome Reserves admits the first band only, and requires it three consecutive years — 2023, 2024 and 2025.

One year of 特A can be weather. Three consecutive years is a property of the district: its water, its soil, its diurnal range, its growers. The rule is deliberately narrow, and it excludes districts that would otherwise be obvious inclusions. That exclusion is the point — a reserve that admits everything grades nothing.

The rule is enforced in the contract, not in a policy document. The mint path stores all three inspection years, checks that each was Special-A, and checks that they are consecutive. There is no path that issues a lot failing that predicate, and the stored years remain readable afterwards so the claim can be re-checked by anyone.

4 · Units

The unit is the whole design. A token that represents "some rice" is a promise; a token that represents one bale in a named lot is a receipt.

• 俵 1 hyō = 60 kg — the traditional bale, and the unit MAFF still quotes the national rice price in. One token is one hyō.
• 石 1 koku = 180.39 L ≈ 150 kg — the Edo tax unit, nominally one person's rice for one year. Domains were ranked by it; the receipts still state it.
• 特A Special A — the top taste band, awarded annually against a blended control.

Total supply is therefore 42,000 tokens against 2,520,000 kg — the same number as the bale count, because the mint path takes its quantity from the warehouse receipt and from nothing else.

5 · Why this chain

Robinhood Chain is an Arbitrum Orbit Layer-2 that settles to Ethereum, uses ETH as its gas token, and exists specifically to carry tokenised real-world assets. Its own flagship instrument is a token conveying economic exposure to an asset a custodian holds elsewhere, with prices published on-chain by oracle.

That is the same shape as a rice bill: custodian off-chain, claim on-chain, price transported separately. Kome Reserves is not adapting itself to a general-purpose chain — it is using a chain whose flagship instrument already has the structure of a warehouse receipt.

6 · Token design

ERC-1155, one token id per warehouse lot. Not ERC-20, and the reason is not stylistic: redemption is lot-specific. A holder does not draw 60 kg from a pool — they draw it from the named lot their receipt refers to. Uonuma rice comes out of the Uonuma vault.

A single ERC-20 supply would make every vault interchangeable, which is precisely the property a 特A grade floor exists to deny. If all eight vaults collapse into one fungible balance, the grade rule stops meaning anything at the point of redemption — the holder gets whatever the pool hands them. One fungible id per lot preserves the binding that the entire admission rule is designed to create.

Lot ids are derived: tokenId = uint64(keccak256("kome.lot:" vault ":" serial)), where serial is the serial printed on that vault's warehouse receipt. The paper and the chain cannot disagree, because one is computed from the other. Vault accounts are derived deterministically from the same vault key, so the account holding a lot can be computed from the receipt alone.

7 · Finality and the receipt lifecycle

An Arbitrum L2 confirms in three stages. A warehouse receipt has also always had three states. They are the same three states — which is why the mapping below required no invention.

Withdrawing to Ethereum via the canonical bridge carries a 7-day challenge period. For a claim on physical rice this is not a defect: it is roughly the time the logistics take anyway.

8 · Issuance and redemption

Issue. Rice is weighed in and the warehouse seals a receipt. The mint path takes the lot id, the supply in hyō, the receipt serial and the three inspection years; it reverts unless the grade predicate passes. Supply cannot exceed the tonnage on the receipt because it is the tonnage on the receipt.

Transfer. Tokens move without the rice moving. This is the Dōjima property, and the only reason the instrument is useful.

Redeem. Burning n tokens against a lot emits the claim the warehouse settles: n × 60 kg from that named lot. Supply retires permanently. The reserve can only ever shrink through redemption, never through a transfer.

Selectors are the first four bytes of the keccak-256 hash of the canonical signature, and are verifiable against any node. Two published selectors are included as a check on the derivation: balanceOf(address,uint256) and the ERC-1155 TransferSingle event topic.

9 · The settlement calendar

Japanese agriculture is scheduled against the nijūshi sekki — the twenty-four points where the Sun's apparent longitude crosses a multiple of 15°. Not months. Rice is planted, drained, headed and stored on this clock, so the reserve counts its stock against it.

立冬 rittō — the start of winter — is the deposit date stamped on every warehouse receipt. All 8 vaults seal within the same fortnight, which is why the reserve has one settlement epoch per year and not twelve. Dates below are computed from solar longitude for 2026, not tabulated.

10 · National context

Japan runs a government rice stockpile, mandated after the 1993 Heisei rice crisis, with a policy target near 1,000,000 t. In February 2025 the government made the first release in the reserve's history — 210,000 t — to arrest a price spike. As of May 2026 the reserve stands near 320,000 t.

Kome Reserves is 0.7875% of that figure. This is stated to be explicit about scale: this is not a systemic reserve and does not present itself as one. It is a small, fully-named, grade-floored parcel whose entire claim is that every bale in it can be pointed at.

11 · Valuation basis

The basis used throughout is ¥46,800 per hyō for Special-A and ¥38,400 for A grade, against a retail reference of ¥50,280 per hyō. At ¥150/USD the reserve's basis value is ¥1,965,600,000 ($13,104,000).

These are basis figures for reconciliation, not a market or a quote. There is no order book, no oracle feed and no price discovery described in this document, and none should be inferred from it.

12 · What can go wrong

• Custody is the whole trust assumption. The contract holds a claim, not rice. If the warehouse does not honour a burn, the token is worth what the counterparty is worth. No chain property changes this.
• Grade is an annual judgement. 特A is awarded by an inspection body against a blended control. A district admitted on three years of 特A can lose the band in year four. The stored years make that visible; they do not prevent it.
• Rice is perishable and seasonal. A bale is not a bar of metal. Storage condition, crop year and moisture all matter, and a receipt dated 立冬 of one year is not interchangeable with the next.
• Lot-specific redemption is a feature with a cost. Because ids are not fungible across vaults, liquidity is fragmented by construction. That is the deliberate trade for the grade floor meaning something.
• Sequencer and bridge risk. Soft confirmations depend on the sequencer; withdrawals to Ethereum carry the 7-day challenge period. High-value actions should wait for Ethereum finality.
• Settlement depends on the chain. The reserve inherits the liveness and security assumptions of the L2 it settles on, including its sequencer and its bridge.

13 · Status and scope

This document describes the reserve's design and its data set. The historical material — the Dōjima rice exchange, the grade rankings, the government stockpile figures and the solar-longitude calendar — is real and sourced.

Nothing here is an offer, a solicitation, or investment advice. Rice is a perishable, seasonal, physically-custodied commodity and a claim on it carries the risks set out in section 12.

Every figure in this litepaper is substituted at build time from the same JSON the website renders from. It cannot drift from the product without the build failing.