This is a Phase 3 open-label crossover study to evaluate the acid-inhibitory effect following 7 days multiple doses of vonoprazan (20 mg per dose) and esomeprazole (20 mg per dose) (Cohort 1) or vonoprazan (20 mg per dose) and rabeprazole sodium (10 mg per dose) (Cohort 2) in healthy Japanese adult male participants (CYP2C19 genotype: EM). There will be a total of 20 participants, 5 per group for both Cohorts 1 and 2. At least 2 participants each with the homo EM (*1/*1) or hetero EM (*1/*2, *1/*3) CYP2C19 genotype will be enrolled among the 5 participants per group.