A relatively new type of juice which has seen its origins in Robertson, South Africa. This type of juice is derived from Jelly Fish Semen mixed with many different types of liquids including a small ratio of alcohol. It’s brewers mainly serve it and have always called it plant juice as the semen in its early stages looks like a plant.
The Kelly family went to the sea to find Jellyfish so that they can start brewing plant juice.
Referred to as such due to the fact that it's a readily available drink option to have while riding a plane, whereas other soft drinks are offered more often under other circumstances, such as at restaurants and supermarkets.
When one wants a soft drink, the first drinks that come to mind are, more often than not, everything else but ginger ale. However, since it's offered at plane rides, ginger ale sometimes associated with them, hence "plane juice".
Flight attendant:
"What would you like to drink? We have coke, club soda and ginger ale."
Passenger:
"YUSSSSS!!! Lemme have some plane juice! Ginger ale!"
I don't buy the schmegegge about Morty sleeping with Moira.
His version of the story was pure schmegegge.
The whole schmegegge was made up to get Liz a little bit of attention.