A Study of Single and Multiple Doses of KW-6356 in Healthy Subjects

Inclusion Criteria: * Individuals who provided freely-given written consent for participating in this study * Men aged 20 ≥ and \< 45 at the time of informed consent; * Japanese individuals without mixed marriage for at least last two generations, for participating Part A and Part B * Japanese and Caucasian individuals without mixed marriage for at least last two generations, for participating Part C * Individuals with BMI ≥ 18.5 and \< 30.0 * Individuals with screening results of; resting pulse rate: 40 to 100 bpm, systolic blood pressure: 91 to 140 mmHg, diastolic blood pressure: 40 to 90 mmHg Exclusion Criteria: * Individuals with any current diseases requiring treatment * Individuals with current cerebrovascular, gastrointestinal, cardiovascular, hematologic, renal, or liver diseases * Individuals with current symptomatic allergy * Individuals with current or past drug allergy * Individuals with current or past psychiatric disorders * Individuals with a history of any autoimmune diseases or malignant tumor * Individuals with alcohol or drug dependence, or those who showed any positive result(s) in drug abuse tests * Individuals with a history of congestive heart failure, hypokalemia, hypocalcemia, or QT prolongation syndrome * Individuals with positive result in any of viral infection tests (HBs antigen, HBs antibody, HBc antibody, HCV antibody, HIV antigen and antibody, and HTLV-1 antibody) or syphilis tests (RPR and TP antibody) at screening. * Individuals with abnormality in standard 12-lead ECG that the investigator or subinvestigator determined as clinically significant at screening, Day -1, and before administration of the study drug on Day 1. * Individuals who participated in clinical trial(s) of any medical products and received administration of those within 4 months prior to the study drug administration in the current study * Individuals who used drugs (including non-prescription drugs, external preparation, vitamins, health supplements, and herbal medicines) within 2 weeks prior to the study drug administration * Individuals who consumed grapefruit, or any food and beverage containing grapefruit or St John's Wort within 1 week prior to the study drug administration * Individuals who smoked or used stop-smoking aid products (including chewing or eating nicotine-containing products, or application of nicotine patches) within 4 weeks prior to the study drug administration * Individuals who admitted to the hospital or had surgery within 3 months prior to the study drug administration * Individuals who had any of the following blood drawing for donation, clinical trial, or any other reasons prior to the study drug administration; ≥ 400 mL blood collection within 3 months; ≥ 200 mL blood collection within 4 weeks; or blood collection for pheresis (such as plasmapheresis or plateletpheresis) donation, clinical trial, or any other reasons within 2 weeks * Individuals who did not agree to use appropriate contraceptive measures from the day of admission to 12 weeks after the last administration of study drug. The appropriate contraceptive measures are defined as refraining from sexual activity or combining two contraceptive methods including condom, oral contraceptives, intrauterine contraceptive devices or pessary. * Any other individuals who were determined as not suitable for participating in this study by the investigator or subinvestigator