1. Written informed consent has been obtained from the participants with an age of over 18 years at the time of signing the informed consent.2. SARS-CoV-2 infection is diagnosed by RT-PCR within 72 hours before starting drug administration.3. Less than six days from onset of COVID-19-related symptoms below to starting the administration of the investigational drug with at least one of the following symptoms observed at the time of enrollment : fever (37.5C or higher), respiratory symptoms (cough, shortness of breath, sore throat, runny nose, etc.), headache, myalgia, malaise, abdominal pain, diarrhea, nausea/vomiting, dysosmia, dysgeusia, or other COVID-19 symptoms defined by investigators or subinvestigators.4. Oxygen saturation (SpO2) measured by pulse oximeter is more than 95%.5. Require no supplemental oxygen.6. Women (less than 12 months after the last menstrual period) who have a negative pregnancy test (urine hCG qualification) and agree to use highly effective contraceptive methods (taking oral contraceptives or use of condom by male partner) during the study period. Investigators or subinvestigators will provide guidance on contraceptive methods.7. Women who are not breast-feeding.

1. Written informed consent has been obtained from the participants with an age of over 18 years at the time of signing the informed consent.2. SARS-CoV-2 infection is diagnosed by RT-PCR within 72 hours before starting drug administration.3. Less than six days from onset of COVID-19-related symptoms below to starting the administration of the investigational drug with at least one of the following symptoms observed at the time of enrollment : fever (37.5C or higher), respiratory symptoms (cough, shortness of breath, sore throat, runny nose, etc.), headache, myalgia, malaise, abdominal pain, diarrhea, nausea/vomiting, dysosmia, dysgeusia, or other COVID-19 symptoms defined by investigators or subinvestigators.4. Oxygen saturation (SpO2) measured by pulse oximeter is more than 95%.5. Require no supplemental oxygen.6. Women (less than 12 months after the last menstrual period) who have a negative pregnancy test (urine hCG qualification) and agree to use highly effective contraceptive methods (taking oral contraceptives or use of condom by male partner) during the study period. Investigators or subinvestigators will provide guidance on contraceptive methods.7. Women who are not breast-feeding.

1. Written informed consent has been obtained from the participants with an age of over 20 years at the time of signing the informed consent.2. SARS-CoV-2 infection is diagnosed by RT-PCR within 72 hours before starting drug administration.3. Less than six days from onset of COVID-19-related symptoms below to starting the administration of the investigational drug with at least one of the following symptoms observed at the time of enrollment : fever (37.5C or higher), respiratory symptoms (cough, shortness of breath, sore throat, runny nose, etc.), headache, myalgia, malaise, abdominal pain, diarrhea, nausea/vomiting, dysosmia, dysgeusia, or other COVID-19 symptoms defined by investigators or subinvestigators.4. Oxygen saturation (SpO2) measured by pulse oximeter is more than 95%.5. Require no supplemental oxygen.6. Women (less than 12 months after the last menstrual period) who have a negative pregnancy test (urine hCG qualification) and agree to use highly effective contraceptive methods (taking oral contraceptives or use of condom by male partner) during the study period. Investigators or subinvestigators will provide guidance on contraceptive methods.7. Women who are not breast-feeding.

1. Written informed consent has been obtained from the participants with an age of over 20 years at the time of signing the informed consent.2. SARS-CoV-2 infection is diagnosed by RT-PCR within 72 hours before starting drug administration.3. Less than six days from onset of COVID-19-related symptoms below to starting the administration of the investigational drug with at least one of the following symptoms observed at the time of enrollment : fever (37.5C or higher), respiratory symptoms (cough, shortness of breath, sore throat, runny nose, etc.), headache, myalgia, malaise, abdominal pain, diarrhea, nausea/vomiting, dysosmia, dysgeusia, or other COVID-19 symptoms defined by investigators or subinvestigators.4. Oxygen saturation (SpO2) measured by pulse oximeter is more than 95%.5. Require no supplemental oxygen.6. Women (less than 12 months after the last menstrual period) who have a negative pregnancy test (urine hCG qualification) and agree to use highly effective contraceptive methods (taking oral contraceptives or use of condom by male partner) during the study period. Investigators or subinvestigators will provide guidance on contraceptive methods.7. Women who are not breast-feeding.