A personal information management system, comprising: a blockchain server configured to store a blockchain including, for each block, a transaction and a transaction ID for identifying the transaction; and a personal information management apparatus configured to access the blockchain server , wherein the personal information management apparatus is configured to store a second piece of personal information on an individual, which accompanies a first piece of personal information for identifying the individual, in association with a first transaction ID received from the blockchain server , wherein the personal information management apparatus is configured to transmit the first transaction ID associated with the second piece of personal information to the blockchain server , delete the second piece of personal information and the first transaction ID, and store, after having transmitted the first transaction ID, a second transaction ID received from the blockchain server , wherein the blockchain server is configured to generate the first transaction ID, generate a first block (BL1) including a first piece of converted data which is based on the first piece of personal information and the first transaction ID, add the first block (BL1) to the blockchain , and transmit the first transaction ID to the personal information management apparatus , and wherein the blockchain server is configured to in response to receiving the first transaction ID from the personal information management apparatus generate the second transaction ID, generate a second block (BL2) including the first piece of converted data and the second transaction ID, add the second block (BL2) to the blockchain , and transmit the second transaction ID to the personal information management apparatus . a blockchain server configured to store a blockchain including, for each block, a transaction and a transaction ID for identifying the transaction; and a personal information management apparatus configured to access the blockchain server , wherein the personal information management apparatus is configured to store a second piece of personal information on an individual, which accompanies a first piece of personal information for identifying the individual, in association with a first transaction ID received from the blockchain server , wherein the personal information management apparatus is configured to transmit the first transaction ID associated with the second piece of personal information to the blockchain server , delete the second piece of personal information and the first transaction ID, and store, after having transmitted the first transaction ID, a second transaction ID received from the blockchain server , wherein the blockchain server is configured to generate the first transaction ID, generate a first block (BL1) including a first piece of converted data which is based on the first piece of personal information and the first transaction ID, add the first block (BL1) to the blockchain , and transmit the first transaction ID to the personal information management apparatus , and wherein the blockchain server is configured to in response to receiving the first transaction ID from the personal information management apparatus generate the second transaction ID, generate a second block (BL2) including the first piece of converted data and the second transaction ID, add the second block (BL2) to the blockchain , and transmit the second transaction ID to the personal information management apparatus . <EOS>