The Antihypertensive Treatment for Acute Cerebral Hemorrhage (ATACH)-II Trial (ClinicalTrials.gov no. NCT01176565; (UMIN 000006526) is an international, multicenter, randomized, concurrently-controlled, parallel arm, Phase III trial to determine the therapeutic benefit of early intensive systolic blood pressure (SBP) lowering compared with standard SBP lowering for acute hypertension in patients with spontaneous intracerebral hemorrhage (ICH). The Trial is funded by the National Institutes of Health in the United States and led by Dr. Adnan Qureshi at the University of Minnesota. Seventeen Japanese institutions will participate in this Trial. This article describes the latest version of the study design and our endeavors to develop the Japanese research network for stroke clinical research. The ATACH-II Trial plans to randomize a maximum of 1,280 (approximately 400 from Japan) subjects who have supratentorial ICH (hematoma volume <60cc) with Glasgow Coma Scale ≥5 and SBP of >180mmHg. Subjects undergo a follow-up assessment for functional and quality of life assessment at 90 days post-randomization. The primary research hypothesis of the trial is that intensive SBP reduction (to ≤140mmHg) using intravenous nicardipine infusion for 24 hours post-randomization reduces the proportion of death and disability at 90 days by ≥10% (absolute) compared to the standard SBP reduction (to 140-180mmHg range) among subjects with ICH whose treatment is initiated within 4.5 hours of symptom onset. The ATACH-II Trial could be the seminal research project for stroke researchers in Japan to demonstrate themselves as effective contributing members of investigator-initiated international clinical trials.