Background
In early August 2025, we received a request for technical assistance from Sato (a pseudonym), a resident of Tokyo.
The problem Sato faced
In September 2024, Sato made a transfer using Bitcoin Core. The transaction completed successfully, but the remaining balance of 33 BTC in the change address did not appear in the wallet.
Sato had consulted several technicians, but none had resolved the issue. Assets worth several hundred million yen appeared to have “disappeared” on the blockchain.
Sato’s situation
- Assets: 33 BTC (worth approximately several hundred million yen)
- Symptoms: The change address balance did not appear in Bitcoin Core
- Transaction records were visible in a blockchain explorer
- Several technicians had already been consulted without a resolution
- Duration: The problem had persisted for approximately one year
- September 2024
After a transfer, the 33 BTC in the change address stopped appearing in the wallet
- October 2024 – July 2025
Consulted several specialists and tried various methods, without success
- Early August 2025
Contacted us for technical recovery as a last hope
- August 31, 2025
Recovery succeeded, and the 33 BTC reappeared in the wallet
Urgent Response
After receiving the request, we immediately recognized the seriousness and complexity of the problem.
Initial assessment
Through a detailed consultation, we established the following:
- The original transaction was clearly visible on the blockchain
- The 33 BTC had indeed been sent to the change address
- The Bitcoin Core wallet was displaying its balance incorrectly
- The issue was related to the wallet’s internal indexing mechanism
Original transfer transaction (September 2024)
Transaction hash: 24f4fa013872c0f04d7f8d9b1a5beed... Block height: 862094 Date: September 20, 2024 Total input: 73.00094827 BTC Output 1 (Binance): 39.99683 BTC Output 2 (change): 33.00090069 BTC → 1M3Q...R8NY
Some transaction details are redacted to protect privacy. Detailed records are available for review at our office
Technical Recovery Process
Phase 1: On-site technical support (late August)
Following an urgent internal discussion, we quickly developed several solutions and made preparations. Our technical team visited Sato to provide on-site support.
Challenges encountered on-site
The problem was more complex than expected and could not be fully resolved within the limited time available that day. Bitcoin Core’s wallet mechanisms involve several technical layers:
- The wallet database’s index structure
- Change address derivation paths
- Transaction record synchronization mechanisms
- The internal logic used to calculate balances
The team promised to continue its in-depth investigation after returning to the office and never give up.
Phase 2: Working through the night on a technical solution (late August–31)
After returning to the office, the technical team persevered, working through the night on repeated investigations and tests.
Technical analysis process
- Analyzed the Bitcoin Core wallet database structure in detail
- Investigated HD wallet derivation path settings
- Checked the indexing status of the change address
- Applied the latest Bitcoin wallet repair technology from the United States
- Tested several database repair methods
- Verified the complete transaction data on the blockchain
Technical breakthrough
The evening of August 31, 2025
The 33 BTC successfully reappeared in the Bitcoin Core balance!
We immediately called Sato with the good news. Deeply moved, Sato told us that after trying everything for nearly a year without success, they had almost given up.
Safely Transferring the Assets (August 31)
Once the balance reappeared, we immediately helped Sato transfer the assets safely.
That same day, Sato transferred the recovered 33 BTC to the OKX exchange for safekeeping.
Asset transfer transaction (verifiable on-chain)
Transaction hash: 95aeff3f6c56f41c08b9777ba6984e2... Block height: 912543 Date: August 31, 2025 Sender: 1M3Q...R8NY (change address) Recipient: 36dR...LHae (OKX exchange) Amount: 33.00062569 BTC Status: Successful
Some transaction details are redacted to protect privacy. They can be verified at our office
- 33
- BTC recovered
- Several hundred million
- Asset value in JPY
- About 1 year
- Duration of the problem
- 100%
- Recovery success
Project Results
| Item | Result |
|---|---|
| Assets recovered | 33 BTC |
| Asset value | Approximately several hundred million yen |
| Issue type | Incorrect balance display for a Bitcoin Core change address |
| Technology used | The latest Bitcoin wallet repair technology from the United States |
Fees explained
| Fee item | Description |
|---|---|
| Initial fee | JPY 0 — Completely free assessment |
| On-site service | Travel and related expenses are covered by the client |
| Technical costs | Covered by us |
| Success fee | Charged only after successful recovery — No charge if recovery fails |
Client Testimonial
“For almost a year, I lived with anxiety nearly every day. The 33 BTC was clearly there on the blockchain, but it would not appear in my wallet. That feeling of helplessness left me close to despair.”
“I consulted several technicians. Some said the wallet was corrupted; others said it was an indexing problem. But nobody could fix it. Some even advised me to give up, saying it was almost impossible to resolve.”
“When your team went out of their way to visit and help me, I was touched, but also anxious. When the first visit did not resolve the problem, I thought I was going to be disappointed again.”
“Even after returning to the office, you kept going, working through the night on your research, and finally got the 33 BTC to reappear. When I received your call on the evening of August 31, I was so moved that I could not speak.”
“Your technical expertise and determination to see this through helped me find hope in the midst of despair. You are more than a technical team—you saved me. Thank you so very, very much!”
Key Factors in the Successful Recovery
In-depth technical analysis
Thorough research into Bitcoin Core wallet mechanisms and the principles of change address indexing
Multiple backup plans
Several solutions prepared in advance to address a range of technical issues
On-site technical support
Direct visits to the client by our team to provide expert service in person
A commitment to see it through
Continued overnight research after returning to the office, persevering until success even when the issue could not be resolved on-site
Technical Advantages
The latest Bitcoin wallet repair technology from the United States
- In-depth understanding of the Bitcoin Core wallet database structure
- Extensive knowledge of HD wallet derivation path mechanisms
- Expertise in algorithms for repairing change address indexes
- Use of the latest wallet database repair technology from the United States
- Extensive experience resolving Bitcoin wallet failures
- On-site technical support services
Common Bitcoin Core Issues
Problems we can resolve
- Change address balances that do not display correctly
- Discrepancies between wallet balances and blockchain data
- Missing transaction records or display errors
- Wallet database corruption or index errors
- Wallet synchronization problems
- Balances that do not appear after importing private keys
Legal Compliance
This case strictly complied with the following requirements:
Ownership verification
- Proof of wallet ownership provided by the client
- Verification of blockchain transaction records
- A signed service agreement
Privacy protection
- Complete confidentiality of client information
- Anonymized transaction details
- A signed nondisclosure agreement
Verifying Authenticity
All data in this case can be verified on the blockchain
Original transfer: 24f4fa013872c0f04d7f8d9b1a5beed...
Recovery transfer: 95aeff3f6c56f41c08b9777ba6984e2...
Anyone can check and verify these transactions using a Bitcoin blockchain explorer.
To protect the client’s privacy, complete transaction details are available for review at our office