Mood: The mood of the video appears to be somber and introspective, with a sense of urgency and concern. The theme seems to revolve around a mystery or a problem that needs to be solved, as hinted by the title 'KYUN RE', which translates to 'Why?' in English. The overall emotion conveyed is one of puzzlement and distress.

Environment: The setting of the video seems to be indoors, possibly a dimly lit room or a space with blurred background elements, suggesting a focus on the individual's emotional state rather than the surroundings. The environment appears to be calm yet tense, reflecting the protagonist's inner turmoil.