Hi,
this is a pretty straight forward achievement which can be earned as soon as you reach the plane in episode one.
You have to enter Amanda's shop at home
and during the flight.
The "at home part" can even be done in the prologue. Just go into the living-room and interact with Amanda in her human form.
When you are on the plane in episode 1, go down the aisle in the cabin. Soon you'll see a white cat sitting on one of the passenger's backrests to your right. Simply enter the shop and buy something, if you want.
The achievement should unlock as soon as you leave the shop.
(video credit: Kicknazz Games)
Hope this helps you guys ;-)
Any improvement? Let me know in the comments below!