diff --git a/registry/eip155/joc.json b/registry/eip155/joc.json
new file mode 100644
index 0000000..352c6fb
--- /dev/null
+++ b/registry/eip155/joc.json
@@ -0,0 +1,32 @@
+{
+  "id": "joc",
+  "shortName": "JOC",
+  "fullName": "Japan Open Chain Mainnet",
+  "aliases": ["evm-81", "joc-mainnet"],
+  "caip2Id": "eip155:81",
+  "graphNode": { "protocol": "ethereum" },
+  "explorerUrls": ["https://explorer.japanopenchain.org"],
+  "rpcUrls": [
+    "https://rpc-1.japanopenchain.org:8545",
+    "https://rpc-2.japanopenchain.org:8545",
+    "https://rpc-3.japanopenchain.org"
+  ],
+  "apiUrls": [
+    { "url": "https://explorer.japanopenchain.org/api", "kind": "etherscan" }
+  ],
+  "services": { "subgraphs": ["https://api.studio.thegraph.com/deploy"] },
+  "networkType": "mainnet",
+  "issuanceRewards": false,
+  "nativeToken": "JOC",
+  "docsUrl": "https://www.japanopenchain.org/en/developer/",
+  "genesis": {
+    "hash": "0x1b54bfa6846a13aacc57066840ec10d1b74b06870539bbc8a3d1b19bdc566733",
+    "height": 0
+  },
+  "firehose": {
+    "blockType": "sf.ethereum.type.v2.Block",
+    "evmExtendedModel": false,
+    "bufUrl": "https://buf.build/streamingfast/firehose-ethereum",
+    "bytesEncoding": "hex"
+  }
+}