The commissioner argues that this court’s decision to decline jurisdiction in the declaratory judgment action is conclusive as to the issues in the *1212BTA case and bars this court from considering the instant appeal. Shaper responds that the declaratory judgment decision and the BTA decision deal with different issues.

A motion to dismiss is not the proper method to resolve the question posited by the commissioner. According to State ex rel. Freeman v. Morris (1991), 62 Ohio St.3d 107, 109, 579 N.E.2d 702, 703, res judicata is an affirmative defense. According to State ex rel. Koren v. Grogan (1994), 68 Ohio St.3d 590, 594, 629 N.E.2d 446, 450, an affirmative defense must be raised and proved, and it usually does not affect the jurisdiction of the court. Further, according to Freeman, the court may not dismiss a case, via a motion to dismiss, on res judicata grounds.

Accordingly, we deny the “motion to dismiss or affirm.”

Motion denied.