Plein enrolled in law studies at the University of Erlangen-Nuremberg before designing luxury dog beds, but did not complete his degree.

[30] Plein's first collections were vintage military jackets which he embroidered with Swarovski skulls and sold at the Maison et Objet in Paris.

[35] 2012: ten boutiques were opened, in Marbella, Moscow Crocus, Baku, Milan, Dubai, St. Petersburg, Seoul, Macau, Amsterdam, and Berlin.

[37] 2013: the opening of stores in Porto Cervo,[38] Moscow, Paris,[39] Miami, Casablanca, Courchevel, Kyiv, Hangzhou, Seoul,[40] and New York.

[41] 2014: store openings include Hong Kong,[42] Los Angeles, New York, Ibiza, Bodrum, Doha, London, and the first Plein duty free at the Vienna airport.

[44][45][46] 2020: show was presented at Social Music City in Milan in June 2019, inspired by Mad Max Fury Road.

[51] Celebrities that have worked with Plein include Mischa Barton, Lindsay Lohan, Snoop Dogg, Rita Ora, Naomi Campbell, Iggy Azalea, Grace Jones, Theophilus London, Fergie, Chris Brown, Jeremy Meeks, Paris Hilton, Mauro Icardi, Alec Monopoly, and Floyd Mayweather.

[59][60] Plein made his entrance into the Web3 space in collaboration with Portion, a blockchain auction house, as well as 3D visual artist, Antoni Tudisco.

[62] Plein participated in Decentraland’s Metaverse Fashion Week in 2022, showcasing a collection of NFT wearables created in partnership with Antoni Tudisco.