'Our Fighting' is a vocal battle theme from Sega's long-running MMORPG Phantasy Star Online 2, performed by voice actress and singer Eri Kitamura in character as Quna (クーナ), a popular idol-like figure within the game's narrative. The track was composed by Hideaki Kobayashi, a veteran Sega sound team member known for his extensive contributions to the Phantasy Star series, with lyrics by Shouko Ohmori. It first appeared on the PHANTASY STAR ONLINE 2 Original Sound Tracks Vol. 2 album released in 2013. The song made its rhythm-game debut in maimai ORANGE PLUS on June 5, 2015, slotted into the GAME & VARIETY category. The maimai version is a shortened edit of the full track, clocking in at approximately 2:10. Over successive maimai versions, the song's in-game genre label changed several times: it was initially classified as GAME during ORANGE PLUS, then reassigned to SEGA from PiNK through FiNALE, rebranded as ORIGINAL at the launch of maimai でらっくす, and finally settled on GAME & VARIETY from でらっくす PLUS onward. 'Our Fighting' also appears in CHUNITHM STAR, where it was added as part of a Phantasy Star Online 2 collaboration MAP event in December 2017 and later made permanently available. In maimai, the song's Master chart (level 12, constant 12.5) was designed by the charter known as 某S氏, noted for a pattern-heavy style, while the Expert chart (level 10+, constant 10.6) was designed by Jack. Notably, the song was removed from Chinese maimai cabinets starting with the 舞萌DX 2023 update and from Asian English cabinets beginning with maimai DX BUDDiES, effectively region-locking it on modern software.