- If you see any Kanji, Hiragana or Katakana texts, then it's possibly Japanese movie. If you see only Chinese characters then it's possibly Chinese movie.
- If you see anything related with Japanese culture and stuff like Samurai swords, Shogun, Sakura, Kimono, Sushi or Anime then it's possibly Japanese movie.
- If you recognized all the actor name are Japanese then it's possibly Japanese movie.
- If you heard the actors said Ohayou Gozaimasu, Konnichiwa, Arigatou, Dame, Yamete, Nissan, Mitsubishi, Toyota or Kawaii, then it's possibly Japanese movie.
- If you recognized the shooting locations in Tokyo, Kyoto or Osaka, then it's possibly Japanese movie.
- If you bought or paid the ticket to watch Kimi no Nawa, Ultraman, One Piece or Jujutsu Kaisen, then you just watching Japanese movie, no doubt !
- If you want more further details what is Japanese or Chinese movies, then learn their languages.