Mm~, maybe.

[Private to Noriko]

I'll give you an idea of how I think this is going to go, dear.

The time those materials of a new Mask appeared, were immediately after a spat occurred between the top and Shiroko, where she went a bit... Psychotic, said things about hating him, tried to hurt him...

Considering that there will be previous implications if he ever thinks about what you decided to do with that "experiment"... Probably not very long.