Hi,Donkya.
Why not allow accounts raised as 警備員 to be promoted to ハンター by purchasing UPLIFT?
However, it is not possible to convert in the reverse direction.
This way, people who enjoyed being a 警備員 will not have to raise a new ハンター from zero and will be able to buy UPLIFT more easily.
It also provides an incentive to continue to buy UPLIFT because once an account is promoted to ハンター, it cannot return to 警備員.