In 2012–13, at the start of the season, Samarin underwent an eye surgery because of a detached retina. Debuting on the ISU Junior Grand Prix (JGP) series, he won a pair of bronze medals at JGP events in Slovenia and Germany and became the first alternate for the 2012–13 Junior Grand Prix Final. At the Russian Championships, he finished eighth in his first senior appearance and then won the silver medal on the junior level. He was assigned to the 2013 World Junior Championships where he finished eighth.