You can check the description of each attribute in Payment endpoints.

Attribute	Child Attribute	Type	Description
id		string	A unique indentifier for the payment.
resource		string	Value is "payment".
status		string	The status of the payment.
amount		integer	The value reflects the amount you specified when requesting the API.
tax		integer	The value reflects the tax you specified when requesting the API.
customer		string	The ID of an existing customer in which to provide payment details for the payment. This or `payment_details` must be present.
payment_deadline		string	Time when the payment will expire. This is a timestamp in ISO 8601 format: YYYY-MM-DDTHH:MM:SSZ.
payment_details		object	A hash or token describing the payment method used to make the payment.
	type	string	value of payment method.
	email	string	The e-mail address used to send the payment receipt and instructions to.
	bank_id	string	A code required by customers when paying with Pay-easy.
	customer_id	string	A code required by customers when paying with Pay-easy.
	confirmation_id	string	A code required by customers when paying with Pay-easy.
	instructions_url	string	A URL for an instructions page
	payment_url	string	URL associated with the payment.
	cvs_code	string	The CVS code (PayEasy)
	store	string	Store slug name e.g. `lawson`, `family_mart`, etc
	confirmation_code	string	A number that customers will need when paying at the konbini (used by some konbini).
	receipt	string	A number that customers will need when paying at the konbini.
	order_id	string	Remitters/payers name customer needs to use to send money as.
	bank_name	string	The name of the bank the user needs to wire funds to.
	account_branch_name	string	The name of the bank branch the user needs to wire funds to.
	account_number	string	The bank account number the user needs to wire funds to
	account_type	string	The type of the bank account the user needs to wire funds to.
	account_name	string	The name of the bank account the user needs to wire funds to.
	payment_deadline	string	Time when the payment will expire. This is a timestamp in ISO 8601 format: YYYY-MM-DDTHH:MM:SSZ.'
	redirect_verify_url	string	URL of the second verification step
	brand	string	Brand of credit card e.g. `visa`, `mastercard`, etc.
	last_four_digits	string	The last four digits of the credit card number
	month	string	Expiry month of the credit card
	year	string	Expiry year of the credit card
	redirect_url	string	URL where customers are redirected after a payment has been completed.
	external_payment_id	string	External Payment ID (PayPay).
	transaction_id	string	Transaction ID
	transaction_key	string	Transaction key
	payment_url_app	string	Payment URL (LinePay)
	payment_access_token	string	Payment Access Token (LinePay).
	charge_key	string	The Charge ID managed by Rakuten Pay
	provider	string	The provider of the carrier billing
payment_method_fee		integer	An additional fee added to specific payment types.
total		integer	The payment total, this is the amount + tax + customer_fee'
currency		string	3-letter ISO currency code used to pay.
description		string	Plaintext description for annotating a resource.
captured_at		string	An ISO 8601 formatted timestamp of when a payment was captured.
external_order_num		string	A unique ID from your application used to track this payment.
metadata		object	A set of key-value pairs.
created_at		string	An ISO 8601 formatted timestamp of when a payment was created.
amount_refunded		integer	Amount refunded
locale		string	Sets the language of instruction page for supported payment methods. Valid options are 'en', 'ja', and 'ko'.
session		string	A "session" represents a secure webpage on which a user can enter payment details.
customer_family_name		string	Customer's family name.
customer_given_name		string	Customer's given name.
mcc		string	Merchant Category Code.
statement_descriptor		string	Used to change the way a payment shows up on a card or payment statement.
refunds		array	Refunds an arbitrary amount of money from an existing payment. If no `amount` is specified, the whole payment is refunded.
	id	string	A unique indentifier for the refund.
	resource	string	Value is "refund"
	currency	string	3 letter ISO currency code used to refund
	payment	string	A unique indentifier for the payment.
	amount	integer	Amount of the refund
	chargeback	boolean	Determine if it's a chargeback
	created_at	string	An ISO 8601 formatted timestamp of when a refund was created.
	description	string	Plaintext description for annotating a resource.
refund_requests		array	A "Refund Request" requests that a payment be refunded manually. This can be used for payment methods that do not support refunds, such as konbini. To support non-refundable payment methods, a bank account must be specified so that we know where to send the funds. Since it is a manual process, the refund will be carried out at a later date, and there's a possibility of it being rejected.
	id	string	A unique indentifier for the refund request.
	payment	string	A unique indentifier for the payment.
	account_number	string	Bank account number
	bank_code	string	Bank code
	bank_name	string	Bank name
	branch_name	string	Branch name
	branch_number	string	Branch number
	created_at	string	An ISO 8601 formatted timestamp of when a refund request was created.
	customer_name	string	Account holder name (kana)
	status	string	Status of the refund request