Effect of Tofogliflozin on UACR Compared to Metformin Hydrochloride in Diabetic Kidney Disease (TRUTH-DKD)

Inclusion Criteria: * Type 2 diabetic patients * Patients aged 20 years or older at the time of obtaining consent * Patients with HbA1c 6.5 or more and 9.0% or less within 13 weeks before obtaining consent (evaluated by test values after 4 weeks or more without taking SGLT2 inhibitor / metformin) * Patients who have been judged by their doctor to need a diabetic drug when they are first seen, or who have already taken a diabetic drug and have decided that it is necessary to add one diabetic drug. * Patients who have been receiving RAS inhibitors (ARB, ARNI, ACE inhibitors, direct renin inhibitors) for 4 weeks or longer * Patients with eGFR of 30 or more (mL / min / 1.73m2) within 13 weeks before obtaining consent (evaluated by test values after 4 weeks or more without taking SGLT2 inhibitor / metformin) * Patients with urinary albumin / creatinine ratio (UACR) of 30 or more and less than 2000 (mg / gCr) (4 weeks or more without taking SGLT2 inhibitor / metformin) within 13 weeks before obtaining consent Evaluate by inspection value) * Patients for whom written consent was obtained based on the patient's free will after receiving sufficient explanation for participation in this study Exclusion Criteria: * Patients receiving treatment with SGLT2 inhibitor or metformin within 13 weeks before obtaining consent * Dialysis patient * Patients with a history of severe hypoglycemia * Patients with hypersensitivity to SGLT2 inhibitor or metformin * Pregnant women, lactating patients, and patients who wish to raise children * Patients with BMI of 35 kg / m2 or more based on the latest measured values within 13 weeks before obtaining consent * Patients who are contraindicated for the study drug * Other patients who the attending physician deems inappropriate as a subject