Advice for obtaining the rail pass once landing in Japan

Hi there

A bit of advice needed - we are planning a 3.5-month trip leaving the UK on July 2nd and arriving in Japan on 7th October for the RWC. I understand the JRP (7 day option) is the best value ticket to buy to allow us bullet train travel from Osaka to Kyoto to Tokyo. However from what I have read the tickets must be bought within three months of the intended travel date. Our issue, however, is that we will be on the road for the majority of our trip and wouldn't trust the delivery to be where we are at that point in time.

Is there another method to receiving the pass? Could we pick it up once we arrive at Osaka Kansai Airport and activate then?

Thanks
Simon