Kobayashi's interest in heavy metal music started around his sixth grade in elementary school after listening to the band Seikima-II.
[3] He joined Amuse in 1996 and spent the early years of his career doing media promotion for visual kei bands such as Siam Shade and Cascade.
[5] After watching Nakamoto's performance, Kobayashi planned to launch a new musical unit combining J-pop and heavy metal with her as the lead singer.
In February 2011, Amuse announced that the members of Heavy Music Club, namely Nakamoto, Mizuno, and Moa Kikuchi, would perform under the name Babymetal.
[9] In June 2022, Kobametal was appointed as a director of Kulture, Inc, an Amuse subsidiary which would handle the integration of new technologies such as the metaverse and NFT into the entertainment industry.