Tokina, Hoya and Kenko are one big happy family. Now, who owns who is besides the point. I am honestly shocked that as a longtime Pentax user, you have not heard of THK, especially since they own Pentax.
The point is Pentax is not independent, unlike Olympus/Panasonic/Sony/Nikon/Canon. In fact, because of the poor sales performance of Pentax in 2008-2009, Hoya's boss was deliberating whether to dump Pentax or not.
See here.
"HOYA's CEO, Suzuki revealed his idea for Pentax digital camera department:
'Don't think keeping (the Pentax digital camera sector) in the HOYA Group forever,
Let it merge with other companies, or independent is also OK.' "
But I suppose they should be alright now. At least, in Japan, they are doing pretty OK.