[2][3] At first, Kobayashi pursued his apprenticeship at the Japan Shogi Association's school in Tokyo; however, he soon began to have health problems, and moved to Nagoya to study under Itaya as a uchi-deshi (a live-in apprentice).
[2][3] Kobayashi became the 40th professional to win his 600th official game when he defeated Kaishū Tanaka [ja] in Meijin Class C1 tournament play on June 9, 2009.
[4] In March 2018, Kobayashi finished the 76th Meijin Class C2 league (April 2017 – March 2018) with a record of 3 wins and 7 losses, earning a second consecutive demotion point which meant he was only one point away from automatic demotion to "Free Class" play.
[5] As a result, he declared his intention to the Japan Shogi Association to become a Free Class player as of April 2018 rather than risk automatic demotion.
[8] The promotion history for Kobayashi is as follows:[9] Kobayashi never appeared in a major title match, but he won two non-major shogi championships during his career: the Young Lions [ja] in 1977 and the Hayazashi Senshuken [ja] in 1994.