A Phase 4 Study to Evaluate Pharmacokinetics and Safety of Darunavir Along With Ritonavir in Healthy Male Japanese Participants

Inclusion Criteria: * Male Participants provided with sufficient explanation of the investigational product, the drugs to be provided and this clinical study prior to the start of participation in the clinical study, and capable of providing voluntary informed consent in writing * Male Participants with a Body Mass Index (BMI) between 18.5 and 25.0 kilogram per square meter (kg/m\^2) at the time of the Screening tests * Non-smokers or male participants who are capable of abstaining from smoking during the period from the day before the Screening tests until the completion of the post-treatment examinations * Male Participants consenting to use a medically-approved contraceptive method (such as condoms or the like) during the period from hospital admission until the completion of the post-treatment examinations * Male Participants showing no clinically significant abnormalities at the time of Screening, on the day prior Exclusion Criteria: * Participants suffering or with a history of diseases related to the liver, kidneys, circulatory system, respiratory system, digestive system, neuropsychiatric system, hematopoietic function or endocrine function and who may be inappropriate for participation in this clinical study * Participants who participated in another clinical study and were treated with another investigational product within 120 days prior to the start of the initial dosing of the provided drugs * Participants giving 200 milliliter (mL) or more of blood within 30 days prior to the start of the initial dosing of the provided drugs or giving 400 mL or more of blood within 90 days prior to the start of the initial dosing of the provided drugs (such as blood donation), or giving a total of 1200 mL or more of blood within the past year * Participants with a history of hypersensitivity to sulfonamide drugs, drug allergies or drug hypersensitivity, alcohol, pharmaceutical or drug addiction, or who may be addicted * Participants with positive results for Human Immunodeficiency Virus antigen or antibodies, Hepatitis C Virus antibodies, Hepatitis B Surface antigen or the serological test for syphilis