Expedition 326 Ultra Deep Riser Top Hole was the first stage of drilling and coring of the Integrated Ocean Drilling Program (IODP) Hole C0002F to the boundary zone between the Philippine Sea and Eurasian Plates in the Nankai accretionary margin, one of the main objectives of the Nankai Trough SEIsmogenic Zone Experiments (NanTroSEIZE) Complex Drilling Program. The expedition objectives were purely operational, with the goal being installation of the wellhead assembly and drilling and casing the uppermost 800 m of the planned 7-km deep hole. Accordingly, no science party was on board during the expedition, and no scientific results are reported. Scientific objectives for the top 1400 m of this Site were previously fulfilled during NanTroSEIZE Stage 1 Expeditions 314 and 315 (Kinoshita et al., 2009). After a one month operation in July-August 2010, Hole C0002F had been drilled to 872.5 m below sea floor (mbsf), and the hole was lined with cemented-in 20-inch casing. A corrosion cap was set in preparation for return to continue drilling in 2012. We confirm that Hole C0002F is now ready for deep riser drilling to the plate boundary fault zone.