[5][6] After graduating from Hokuriku, Kobayashi joined Artista Asama in the Japanese regional leagues in 2015.
After one year, he joined lower tier Thailand side Nakhon Phanom, marking his first professional contract.
[8] In 2018, he would go to Cambodia to sign for league heavyweights Svay Rieng as their AFC player quota.
[12][8][13] Kobayashi would leave Cambodia[14] and try out for the first team of Liga 1 side Persija Jakarta, playing two matches in the President's Cup in 2022.
[15][16] However, he didn't make the cut, and rejoined the Cambodian league later that year with National Defense Ministry.