Japanese brand Vessel has made a lovely adapter for half moon screwdriver bits

[Altan]

The photo tells everything already.

 

 

 

[Altan]

Just be careful when you purchase Japanese hex shank products to not get a wrong item, as Japanese hex shank is a bit longer than the Western one, they make the same adapter for Japanese market with longer hex shank. 

 

 

 

[Altan]

Here is another adapter for half moon bits.