Study to Evaluate the Efficacy and Safety of Combined Administration of TAK-536CCB and Hydrochlorothiazide in Patients With Grade I or II Essential Hypertension.

TAK-536CCB 20 mg/5 mg ＋Hydrochlorothiazide placebo tablets

TAK-536CCB 20 mg/5 mg and Hydrochlorothiazide 6.25 mg tablets

TAK-536CCB placebo and Hydrochlorothiazide 6.25 mg tablets

TAK-536CCB placebo and Hydrochlorothiazide 6.25 mg tablets x2

TAK-536CCB 20 mg/5 mg and Hydrochlorothiazide 6.25 mg tablets x2