Takeda no longer does AS but the difference is in the thinness (AS being thinner) a thread below maybe helpful
https://www.chefknivestogoforum.com/takeda-as-vs-nas-t10703.html
Selling my 240mm NAS gyuto from Takeda. Only used for two weeks as I ended up scoring an AS model
Price : $400 -Reduced $325 USD via PayPal only shipping in the US
Getting ready to marinade 7 pounds of bone in short ribs via the Julia Child method witg red wine, brandy and olive oil. Oil pairing it with this Magnum tomorrow for dinner.