If this file is a standard music video (MV) or a fan-made edit, it typically features:
"Gizen" often refers to the track "Bitter Choco Decoration" by the famous Vocaloid producer syudou . b_Bd_Gizen)mp4
Often features Hatsune Miku or characters from the mobile game HATSUNE MIKU: Colorful Stage! (Project SEKAI), specifically the group Nightcord at 25:00 . If this file is a standard music video