Located in Higashijonan, Oyama City, Tochigi Prefecture, Toshima Internal Medicine Clinic is an internal medicine clinic that opened in October 2022. Dr. Masaki Toshima, the director, graduated from Nagasaki University and has approximately 30 years of experience at the Self-Defense Forces Medical University Hospital. He is a specialist with multiple certifications including Certified Physician and Instructor of the Japanese Society of Internal Medicine, Specialist and Instructor of the Japanese Society of Hematology, Certified Physician and Instructor of the Japanese Society for AIDS Studies, as well as qualifications as a smoking cessation supporter and Infection Control Doctor (ICD). With the philosophy "Focusing on community health and providing trusted healthcare," the clinic offers general internal medicine services along with specialized care in hematology and infectious diseases. The infectious disease outpatient clinic is operated on an appointment-only basis. The clinic also provides vaccinations including influenza and COVID-19, as well as health checkups, supporting preventive medicine in the community. Operating hours start at 7:30 AM, featuring early morning appointments convenient for the working generation, and English-language consultation is available. The clinic accepts cashless payments via credit cards and electronic money, provides on-site parking, and is equipped with barrier-free facilities, creating an accessible environment for diverse patients.