To Evaluate Efficacy and Safety of Z-215 in Erosive Esophagitis

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) .