The following points are posted on the Financial Services Agency’s website
Based on the crypto-assets exchange operator’s explanation, the crypto-assets that are supported by the crypto-assets exchange operators in this list confirms only that they follow the definition under the Payment Service Act.
The Financial Services Agency and Treasury do not guarantee or endorse the value of these crypto-assets. Crypto-assets are not necessarily backed by assets.
The following are disclaimers when trading a crypto-assets.

(Disclaimers concerning the use of crypto-assets)
Crypto-assets are not a “legal tender” with values guaranteed by the country, such as the Japanese yen or dollar. They are electronic data exchanged on the Internet.
The price of crypto-assets may fluctuate. There is a possibility of losing money as the price of the crypto-assets may decrease significantly and suddenly become worthless, and so on.
The crypto-assets exchange operator must register with the Financial Services Agency/Finance Bureau. Please check whether or not the exchange is a registered business if using their services.
When trading crypto-assets, please seek explanations from the operator, fully understand the transaction details, and decide at your own discretion.
Inquiries about crypto-assets and fraudulent coins are on the rise. Please be cautious of malicious and fraudulent businesses who uses a crypto-assets and leverages the news of new crypto-assets exchange operator.
Crypto-assets exchange registration list