Patrick Frater Asia Bureau Chief Japanese animated film “The First Slam Dunk” has taken a strong early lead at the mainland China box office, picking up $13.8 million on its Thursday opening day. Films mostly release in China on Fridays, but the Japanese hit was given previews on Wednesday and a full court release on Thursday, starting with widespread midnight screenings. Data from local firm Ent Group reveals that the film earned $3.16 million from some 14,000 preview screenings on Wednesday, followed by $13.8 million on Thursday from 184,000 screening sessions. That gives it a $17 million cumulative and positions it at the top of the box office chart even before the conventional Friday to Sunday weekend begins.