Since Sharp are now duly executing a programme to provide at least two major updates (OS upgrades) within a period of two years, Japanese carriers are announcing which models will receive the upgrade to Android 9.0 Pie. Upgrades will not beging to roll out before late November 2018, but will most likely become available in the first quarter of 2019.
On AU by KDDI:
On UQ Mobile:
For models to receive an upgrade to Android 8.0, click here.