There are three Otsuka pharmaceutical industry companies in the U.S.:

Otsuka America Pharmaceutical, Inc. (OAPI) successfully commercializes Otsuka-discovered and in-licensed products in North America.

Otsuka Pharmaceutical Development & Commercialization, Inc. (OPDC) clinically develops and registers innovative healthcare products on a global basis.

Otsuka Maryland Medicinal Laboratories, Inc. (OMML) is a basic research center investigating pharmacological compounds.