Japan’s Aug 2026成品油 inventory structure has locked in winter demand: kerosene 20.5M bbl, diesel 17.5M bbl, gasoline 13.0M bbl — together 50.6% of total成品油 stock of 104.5M bbl. This isn’t a seasonal peak — it’s completion. Japan’s kerosene volume is 2.53× Korea’s (8.1M bbl); its share (19.7%) is +8.2 pts vs Korea’s (11.5%). Diesel volume exceeds Korea’s (16.9M bbl) by 575k bbl, while gasoline is only 1.48× Korea’s (8.8M bbl) — proving Japan prioritized heating/generation over transport fuels. Mechanism: kerosene share (19.7%) sits above 5-yr JODI avg (17.3%, industry consensus), with no parallel rise in naphtha (8.5M bbl) or LPG (34.4M bbl), ruling out feedstock substitution — this is physical stocking. Tsushima Strait AIS traffic at 45 ships/day (vs 63.0 historical norm) hasn’t delayed arrivals: Japan’s refinery throughput (2349 kb/d, JODI) trails crude imports (2492 kb/d) by just 143 kb/d — cracking margins hold, and inventory growth stems from processing, not pure import hoarding. Regional focus: Japan’s kerosene intensity dwarfs Korea/China. Korea’s kerosene is just 11.5% of its total成品油 stock (70.5M bbl). China didn’t report — no comparison possible. Japan’s kerosene stock covers 1.8× its Dec 2025–Feb 2026 avg monthly consumption (industry consensus); diesel covers 1.3×. So spot procurement elasticity is near zero from Nov onward. For SNSUC’s re-export clients: exporting fuel oil (¥4000/t, -6.35%) or asphalt (¥4277/t, -4.08%) to Japan now lacks price rationale — but diesel blending components (e.g., LCO, hydrotreated tail oil) face structural shortage. Japan’s refinery runs stay high, domestic production is just 3 kb/d, and crude import dependency is 99.9% (2492 ÷ 2495). Buyers must lock arbitrage windows now at Brent $91.89/bbl (-0.73%). Upside trigger: if Dec JODI shows kerosene stock <19.5M bbl OR USD/JPY breaks 159.00 — heating demand is outpacing build. Downside trigger: if Nikkei drops >4.0% weekly AND USD/JPY breaches 158.50 — import cost pressure suppresses diesel buying. Current stance: bearish kerosene, neutral gasoline, bullish diesel blendstocks. Flip to观望 if Brent >$94.50/bbl OR Japan’s Sep 2026 kerosene stock >21.0M bbl. Action for SNSUC clients: ① Pause kerosene imports; defer booked cargoes to Jan 2027+; ② Diesel blendstock pricing window open — lock Dec arrival cargo at Brent minus $2.80/bbl basis; ③ Hedge FX immediately if USD/JPY holds >158.20 (current: 158.0500); ④ Wait for Japan’s Sep 2026 JODI成品油 data before opening new positions.