Mood: The mood of the video appears to be melancholic and introspective, with a hint of nostalgia. The theme seems to revolve around relationships, love, or heartbreak, given the title 'Kyon' which translates to 'Why' in English. The overall emotion conveyed is one of longing and possibly regret.

Environment: The setting of the video seems to be outdoors, possibly in a rural or natural environment, given the blurred background that appears to be trees or foliage. The focus is on the characters and their emotions rather than the surroundings, suggesting that the story might delve into personal and emotional journeys.