With his impulse to sensationalize, Japanese filmmaker Sion Sono broadcasts the internal minutiae of his characters as something bolder, transforming Cold Fish from an exploration of jealousy, desire, pride, ego, and personal disappointment into a perversely comic Grand Guignol. The owner of a struggling fish store is unexpectedly taken under the wing of a much more successful proprietor and soon learns that shopkeeper’s shady techniques in business, life, love, and murder. Sono takes the procedural patience of Zodiac and turns it inside out; instead of tracing the steps of how to find a killer, he rather exactingly and methodically assays how to become one. The film’s gory high-body-count climax is by turns terrifying and sickening, queasily funny, and, finally, impishly insolent. As the maniacal killer, the actor Denden brings a loopy charisma and offbeat intensity, scary and goofy at the same time. His unlikely student Mitsuru Fukikoshi remains shy and ambivalent, a helpless bystander in his own life even as his hands become increasingly bloody. In comparison with the maximalist four-hours-plus of Sono’s 2008 Love Exposure, the running time of Cold Fish feels downright breezy at a mere two and a half hours. The film moves at a brisk pace with an absurdly extended climax of unhinged rage and debauched butchery that goes on for nearly an hour. Sono’s sense of time and pacing is purely his own, drawn perhaps from his background with the idiosyncratic ebb and flow of poetry. Cold Fish is wild, head-turning, stomach-churning stuff, and it makes a bracing addition to the overstuffed canon of serial-killer cinema.