As the world’s third-largest movie market by box-office revenue, Japan is enjoying a summer packed with 大ヒット (dai hitto, blockbusters) from 「スパイダーマン：ブランド・ニュー・デイ」 (Supaidāman: Burando Nyū Dei, “Spider-Man: Brand New Day”), which opened on July 31, and Christopher Nolan’s 「オデュッセイア」 (Odyusseia, “The Odyssey”) coming Sept. 11.

Yet the season’s breakout hit so far is「映画ちいかわ 人魚の島のひみつ」 (Eiga Chiikawa Ningyo no Shima no Himitsu, “Chiikawa the Movie: The Secret of Mermaid Island”).

Adapted from the popular manga and anime series “Chiikawa,” the franchise’s first feature film has earned more than ¥4.4 billion ($28 million) since opening on July 24. Its first three days at the box office ranked as the ninth-biggest opening in Japanese history, sparking 口コミ (kuchikomi, word-of-mouth) buzz and heated discussion online as surprised viewers said it felt like more of a ホラー映画 (horā eiga, horror movie) than a 子ども向け映画 (kodomo-muke eiga, film for children).