You can make a purchase as a guest without creating an account. During checkout, you will be asked to enter your name, phone number, email address, and optional details such as notes, account registration, and email subscription preferences.
If you prefer to limit the personal information you provide, you may use a nickname instead of your real name and enter a placeholder number for the phone field. However, please make sure to use a valid email address, as it is required to receive order confirmations and to be contacted in case of any issues.
Reference: Order process (STORES FAQ)

• Credit Cards: VISA, Mastercard, American Express, Diners Club, JCB
• Convenience Store Payment: FamilyMart, LAWSON, MINISTOP, Seicomart, Daily Yamazaki
• PayPal
• Rakuten Pay
• PayPay

An e-commerce platform is the system used to build and operate an online shop. This site uses STORES, a widely used platform in Japan.