Why do you think they are fake ? In Singapore it is common to find grips packaged like this including Yonex
So far , have not come across any YY grip packaged like this , I have only seen Victor , Whipper n Gosen in this form.
These grips are no good. Last about one hour at best. The only thing good is, if you have sweaty hands, these grips feels dry and can absorb a lot of crap. Stay away!! I would recommend Pro Supex or Wilson grips. The PS can last >10 hours of play. Wilson can do perhaps 6-8 but it's thinner. Fortune is good for sweaty hands and last really long, but it's thick.