The purpose of this study is to investigate how the body processes prasugrel and how prasugrel affects blood clotting in healthy Korean men. Three different dosing regimens of prasugrel will be given. Information on side effects will also be collected.

Inclusion Criteria:

• Are overtly healthy males, as determined by medical history and physical examination.
• Are between the ages of 20 and 45 years, inclusive.
• Have a body mass index (BMI) of 19 kg/m^2 to 27 kg/m^2, inclusive, at screening.

Exclusion Criteria:

• Are currently enrolled in, or discontinued within the last 60 days from a clinical trial involving an investigational drug or device, or are concurrently enrolled in any other type of medical research judged not to be scientifically or medically compatible with this study.
• Have known allergies to prasugrel or related compounds.
• Are persons who have previously completed or withdrawn from this study or any other study investigating prasugrel.
• Self-reported history of significant bleeding from trauma (for example, prolonged bleeding after tooth extraction).
• History of major surgery within 3 months of screening or planned surgery within 14 days after the last day of dosing.
• Have a platelet count of <100,000/(cubic millimeters) mm^3 at the time of screening.
• Have tested positive for fecal occult blood at screening.
• Have significant prolongation of prothrombin time (PT) or activated partial thromboplastin time (APTT) at screening.
• Have a clinically significant abnormality following the investigator's review of the physical examination, electrocardiogram (ECG)and clinical (safety) laboratory tests at screening.
• Personal or first-degree family history of coagulation or bleeding disorders (that is, hematemesis, melena, severe or recurrent epistaxis, hemoptysis, gastrointestinal ulcers, hemorrhage, clinically overt hematuria or intracranial hemorrhage) or reasonable suspicion of vascular malformations, for example, cerebral hemorrhage, aneurysm or premature stroke (cerebrovascular accident [CVA] <65 years of age).
• Have significant active hematological disease and/or whole blood donation of more than 400 mL within the last 2 months and component blood donation within the last month.
• Volunteers who have an average weekly alcohol intake that exceeds 21 units per week or volunteers unwilling to adhere to study alcohol restrictions during the study (1 unit = 360 mL of beer; 150 mL of wine; 45 mL of distilled spirits).