Okuyama Naika Clinic, located in Izumi-cho, Kokubunji City, Tokyo, is a specialized internal medicine clinic. The clinic operates on a two-shift schedule on Mondays, Tuesdays, Thursdays, and Fridays, with morning sessions (9:00 AM to 12:00 PM) and afternoon sessions (4:00 PM to 6:00 PM), while Saturday consultations are morning-only (closed on the 2nd and 4th Saturdays). Starting from fiscal year 2025, the clinic participates in Kokubunji City's gastric cancer screening program, offering less invasive transnasal endoscopy (stomach camera through the nose). Patients can use the city's screening vouchers for gastric cancer examinations, making the clinic an important contributor to regional preventive healthcare. The facility was rebuilt and reopened in November 2022, featuring barrier-free accessibility. The clinic also provides parking facilities and accepts credit cards and electronic payments, offering convenient payment options. As a community-based internal medicine clinic, it offers comprehensive services ranging from daily health management to medical screenings.