A Study With [18F]MNI-1054 to Determine Lysine -Specific Demethylase 1A (LSD1) Brain Enzyme Occupancy of TAK-418 After Single-Dose Oral Administration in Healthy Participants

Inclusion Criteria: 1. The participant must have a body mass index (BMI) greater than or equal to (\>=) 18.5 and less than or equal to (\<=) 30.0 kilogram per square meter (kg/m\^2) at the screening visit. 2. The participant must be a current nonsmoker at screening as demonstrated by negative cotinine test. 3. The participant has adequate circulation to both hands for safe placement of arterial lines (as determined by Allen's test). Exclusion Criteria: 1. Has a known hypersensitivity to any component of the formulation of TAK-418 or related compounds, including \[18F\]MNI-1054. 2. The participant has a positive alcohol or drug screen. 3. The participant has a history of alcohol consumption exceeding 2 standard drinks per day on average (1 glass is approximately equivalent to the following: beer \[354 milliliter (mL)/12 ounce (oz)\], wine \[118 mL/4 oz\], or distilled spirits \[29.5 mL/1 oz\] per day). 4. The participant consumes excessive amounts, defined as greater than 6 servings (1 serving is approximately equivalent to 120 mg of caffeine) of coffee, tea, cola, energy drinks, or other caffeinated beverages per day. 5. The participant has a substance abuse disorder. 6. The participant cannot tolerate venipuncture or has poor venous access that would cause difficulty in collecting blood samples. 7. The participant has contraindications to undergoing magnetic resonance imaging (MRI) examination including but not limited to implants, such as implanted cardiac pacemakers or defibrillators, insulin pumps, cochlear implants, metallic ocular foreign body, implanted neural stimulators, central nervous system aneurysm clips, and other medical implants that have not been certified for MRI, or history of claustrophobia in MRI. 8. The participant has clinically significant abnormal findings on brain MRI scan that in the opinion of the investigator may interfere with the interpretation of the PET imaging. 9. The participant has experienced an acute illness within 10 days before the screening visit. 10. The participant has a risk of suicide according to the investigator's clinical judgement per the Columbia-Suicide Severity Rating Scale at screening or has made a suicide attempt in the 12 months before screening. 11. The participant has luteinizing hormone, follicle stimulating hormone (FSH), or estradiol levels that are clinically abnormal. 12. The participant has existing skin rashes that can be diagnosed as dermatitis.