Katana slot from Novomatic has been released before under the name "Shogun". We don't know what was the reason of the name change, but after the rebranding of the slot game in "Katana" the number of fans have been increased every year.
Right now Novomatic is the proud owner of one the biggest top hit on the slot machines market. Maybe the samuray games are meant to be always successful.
Play it and enjoy it!