Yes, you can. You do not need a finalized itinerary to purchase your Japan Rail Pass. During the online ordering process, you only need to provide an approximate start date.

• 90-Day Validity: The Exchange Order (voucher) is valid for 90 days (3 months) from the date of issue. You must exchange it for the actual pass in Japan within this window.
• Activating the Pass: Your final start date will be officially decided when you visit a JR Exchange Office in Japan. You can choose any start date that falls within 30 days of the exchange date.

Please ensure that your estimated travel period falls within the 3-month validity of the voucher issued by JTB.