Ultraman Gaia: Gaia Again (2001)

Ultraman Gaia: Gaia Again 2001 / ウルトラマンガイア ガイアよ再び 2001 / Ultraman Gaia: Once Again Gaia , Ultraman Gaia: Gaia yo Futatabi , Urutoraman Gaia: Gaia yo Futatabi

After the battle against Zogu was over, both Gamu and Fujimiya began to live normal lives until another threat arrives on Earth - a surviving monster soldier of Zogu's army named Gakuzom. (Source: Ultraman Fandom Wiki)