Although Volca and FC Kagoshima had applied for J.League Associate Membership separately, both sides restarted their talk about the merger, then finally agreed with merging their clubs to aim promotion to the J.League, in response of the advisory by the J.League organization.

On 2 December 2023, Kagoshima United secure promotion to J2 League from 2024 after draw against Gainare Tottori 1–1 and back to second tier after 4 years since 2019.

On 27 October 2024, Kagoshima United officially relegated to J3 League after defeat from V-Varen Nagasaki 4-1 and ending one year in second tier.

The traditional rival of Kagoshima United is Roasso Kumamoto, the prefectural neighbours and former Kyushu Soccer League fellows since 1983 until 2005, except 2001–2002.

Note: Flags indicate national team as defined under FIFA eligibility rules; some limited exceptions apply.

Note: Flags indicate national team as defined under FIFA eligibility rules; some limited exceptions apply.