Study to Evaluate the Efficacy and Safety of Tacrolimus in Kidney Transplant Recipients (BLOSSOM)

Inclusion Criteria: * Over 20 years old(male or female) * Patients with eGFR (By CKD-EPI) ≥30mL/min/1.73m\^2 and spot urine P/C ratio≤0.5 at screening test * Patients who are taking Tacrolimus twice a day for maintenance therapy and have Trough level of 3\~10ng/ml * Agreement with written informed consent Exclusion Criteria: * Patients who have transplanted organs other than kidney * Patients with acute rejection who have been clinically treated within the last month * Patients who have changed their administration of adjuvant immunosuppressants and corticosteroids within the last month (dose change, discontinuation, etc.) * Patients who have been diagnosed with cancer within the last 5 years (except skin cancer or thyroid cancer determined by the investigator that treatment has been completed) * Patients deemed inappropriate for screening due to severe digestive disorders at screening * Patients with severe systemic infections requiring treatment (transplantation may be possible after the infection is completely lost or controlled) * Patients with genetic problems of galactose-intolerance, Lapp lactose deficiency or glucose-galactose malabsorption * If the following cases occur during screening * Treatment of active liver disease or increased one or more of the liver function tests (T-bilirubin, AST, ALT) levels more than three times the upper limit of normal range * Patients with WBC \<2,500/mm\^3, PLT \<75,000/mm\^3, ANC \<1,300/μL * Patients who have experienced hypersensitivity reactions or serious abnormalities with medicines used in this clinical trial or with similar chemical structures (Tacrolimus, etc.) * Pregnant or lactating women * Patients of childbearing potential who do not agree to the proper use of contraception during the trial * Patients who received other investigational drugs within 4 weeks prior to consent of the document * Patients unable to participate in the clinical trial due to the judgment of other investigators