In his youth, he made a name for himself as a libertine.
Someone who avoids work and indulges in leisure or hobbies. Often carries a critical tone.
That lazy person spends all day playing pachinko.
hobbyist; enthusiast
A person deeply absorbed in a hobby or pastime, sometimes to the point of neglecting other responsibilities. Can be used affectionately or critically depending on context.
My father is a fishing enthusiast and always goes out to sea on weekends.