Located in Yotsuya Saneicho, Shinjuku Ward, Tokyo, Tanaka Naika Clinic is an internal medicine clinic situated along Sanei-dori, approximately a 5-minute walk from JR and Tokyo Metro Yotsuya Station. Established in 1956, the clinic has a long history of supporting community healthcare, with occupational health services as a core focus of its practice. Its treatment philosophy emphasizes careful explanation of medical conditions through consultation, examination, and testing, ensuring patients fully understand before proceeding with treatment. The clinic aims to serve as a primary care physician for those unsure which medical facility to visit, addressing a wide range of internal medicine conditions. The medical director graduated from Sapporo Medical University School of Medicine and previously worked at the National Center for Global Health and Medicine. English-language services are available, and the clinic accepts credit cards and electronic payments, flexibly accommodating diverse payment needs. The facility features barrier-free design, providing an accessible environment for patients with physical concerns. Consultation hours follow a two-session format: mornings (9:00 AM - 11:45 AM) and afternoons (3:00 PM - 6:00 PM), with Thursday afternoon reception starting at 4:00 PM.