Yes you make an outbound one way booking, online if you want to avoid the telephone fee.

Then later call to add the inbound and they’ll deduct the extra avios and fees. If you want to add the inbound on release at 1am call Japan.

Or or if you have enough avios, you can book the inbound at full price and call in the morning to have to vouchered (half avios returned). But fees will be different done this way (generally higher to the US, lower to Asia).