Premise: The Takahashi River (高梁川 , Takahashi-gawa ) is a Class A major river in the western part of Okayama Prefecture. It acts as the main drainage for the Takahashi River Drainage System, and is one of the three main drainage rivers in Okayama Prefecture (the others being the Yoshii River and the Asahi River).
Hypothesis: Yoshii River is a major drainage river.