Kawaguchi Naika Ganka Clinic, located in Shirakawa, Koto Ward, Tokyo, provides specialized medical care in both gastroenterology and ophthalmology. The director, Dr. Yoshiaki Kawaguchi, is a certified gastroenterology specialist with extensive experience treating digestive diseases, particularly focusing on intestinal disorders. The clinic features a unique two-specialist system with his wife, Vice Director Dr. Nanae Kawaguchi, overseeing the ophthalmology department. In gastroenterology, the clinic performs stomach and colon endoscopies using thinner scopes combined with intravenous anesthesia to reduce patient burden. Polyps discovered during examination can be removed on the spot. The ophthalmology department handles visual field testing, amblyopia screening, contact lens prescriptions, and addresses a wide range of eye-related symptoms. The facility is barrier-free designed, making it accessible for strollers and wheelchairs. Payment options include cash, credit cards, and QR code payments, while a web reservation and questionnaire system helps minimize waiting times. Consultation hours are from 9:30 AM to 1:00 PM and 2:30 PM to 7:00 PM, with weekday appointments available until evening.