Kostas Arsenis was born in Larisa, where he received his first electric bass, classical guitar and music theory lessons. He continued his studies at the National University of Music in Bucharest and the Department of Music Studies of the National and Kapodistrian University of Athens. He then studied electric bass at the Filippos Nakas Conservatory with Yiotis Kiourtsoglou and double bass with Anastasios Kazaglis at the Athens Conservatoire.

Since he was very young he became active in music as a member of many bands (Frog String Trio, Athens Tango Ensemble, Athens Theater Orchestra, Alkman, Kanon Orchestra, Havana Tango trio, Taboo trio, Diminuita Swing Trio, Ektos Eaftou, Brasilentina, Swinging Cats, Swinging Tyranhas).

Since 2009 he teaches double bass, electric bass and music theory at schools and conservatories. He has collaborated with many well-known artists (Alkistis Protopsalti, Kostas Hatzis, Orfeas Peridis, Dionysis Savvopoulos, Mimis Plessas and more).