The purpose of this study is to evaluate the efficacy and safety of Z-215 (10 mg, 20 mg, 40 mg) , compared with Rabeprazole Sodium 10mg in patients with erosive esophagitis of Grade A to D as defined by the LA classification grading system.

Inclusion Criteria:

• In observation period, the participant must have endoscopically confirmed erosive esophagitis of Grade A to D, as defined by the LA classification grading system, and the target number of participants who are clearly Grade C or D is 20% (96 participants) or more of the total participants.
• Outpatient (including inpatient for examination)

Exclusion Criteria:

• Participants with a previous or current history of eosinophilic esophagitis,scleroderma, esophageal stenosis, esophageal varices, Barrett's esophagus ( columnar epithelium metaplasia>=3 cm ) or high-grade dysplasia.However, participants with Schatzki's ring ( >=20mm ) are allowed to be included.
• Participants who have acute upper gastrointestinal bleeding, gastric or duodenal ulcer (mucosal defect with white coating>=3mm) within 28 days prior to observation period . Participants with above disease at endoscopy during the observation period.
• Participants with Zollinger-Ellison syndrome.Participants with suspected gastric acid hypersecretion disorders attributable to hyperparathyroidism and others.
• Participants with a previous history of surgery of esophagus,stomach or duodenum (excluding removal of benign polyp by endoscopic polypectomy) .