noun
Used for someone who passionately loves or is deeply devoted to a particular field, art, or activity, such as cinema, music, or literature. Often appears in compounds like 映画熱愛者 (cinema lover).
彼はクラシック音楽の熱愛者だ。
He is a devotee of classical music.
映画熱愛者のための上映会が開かれた。
A screening was held for cinema lovers.
ファン is a casual loanword for 'fan', whereas 熱愛者 is a more formal, literary term implying intense love or dedication.
Compound of 熱愛 (passionate love) + 者 (person). The word is transparently derived from its components.