Inclusion Criteria:  Persons who meet all of the following criteria will be eligible for this clinical trial.  Males and females who are 20 years of age or older at the time of obtaining consent Those who are confirmed positive for SARS-CoV-2 by antigen test or RT-PCR test using specimens (nasopharynx, nasal cavity, oropharynx, or saliva) collected within 72 hours prior to obtaining consent. Those who have fever symptoms (37.5 degrees Celsius or higher) at the time of screening test. Patients who have at least one symptom with a score of 2 or higher among the symptoms of myalgia, sore throat, diarrhea, nausea, vomiting, cough, and shortness of breath at the time of the screening test. Patients with a blood oxygen saturation (SpO2) of 96 % or higher during room air inhalation at the time of the screening test  Exclusion Criteria:  Subjects who meet any one of the following criteria will be excluded from this study.  Patients who have had symptoms caused by COVID-19 for more than 6 days on the day of initiation of study drug administration (Day 1) with the day of onset of symptoms as Day 0. Patients who need to receive concomitant therapy or administration of prohibited drugs during the study period Patients who have taken or received drugs that have or may have antiviral activity against SARS-CoV-2 within 2 weeks prior to the start of study drug administration. Patients currently using antiviral drugs Patients with suspected complications of infectious diseases other than COVID-19 Subjects with a history of COVID-19 within 1 month prior to obtaining consent Patients whose body weight at the time of screening test is less than 25 kg or more than 127 kg (the first decimal place of body weight shall be rounded off) Patients undergoing dialysis treatment Patients wno have severe liver dysfunction (hepatic dysfunction, hepatic fibrosis, etc.) Patients with poorly controlled hypertension (systolic blood pressure (SBP) of 180 mmHg or higher or diastolic blood pressure (DBP) of 110 mmHg or higher) Patients with complications of diabetic retinopathy, diabetic nephropathy, or diabetic neuropathy Patients with heart failure of NYHA Class III or higher Patients with malignant tumors or those judged to have a high possibility of recurrence Patients requiring oxygen therapy A person who has a complication of methemoglobinemia or any other disease that may cause measurement error of the pulse oximeter Patients with a history of serious drug allergy (anaphylactic shock, etc.) Pregnant women, lactating women, or women who plan to become pregnant or lactate during the study period Subjects who have had more than 400 mL of whole blood drawn within 16 weeks or more than 200 mL within 4 weeks prior to obtaining consent, or component blood (plasma and platelet components) drawn within 2 weeks Patients who have been administered IVM. Those who have participated in other clinical trials and received medication at the time of obtaining consent, or those who have received an investigational drug other than placebo for less than 16 weeks Others who are judged by the investigator or others to be inappropriate to participate in the study.