Both films are slice-of-life, they focus on the everyday lives of their characters rather than a distinct plot. They're visually stunning, with beautiful aesthetics and cinematography. And they have a melancholic tone.
"One Day Off" and Perfect Days" are slice of life about introverted main characters in their simple and peaceful yet fulfilling and adventurous lives. Enjoying the little things in the world and finding comfort by yourself.
Both of the movies are about appreciating the small things in life as their themes. Both of them follows a protagonist and how they live their life. Both are very slow paced but they make you appreciate life.
They are not same, but I believe if one loves to watch the "Perfect Days", she/he might love "Little Forest" too. Both portray solitude and how to be happy by your own company.
