An agent for modulating the function of an RFRP receptor, characterized by containing either a compound represented by the formula (I) ##STR00001## [wherein ring A represents an optionally substituted aromatic ring; ring B represents an optionally substituted benzene ring; X represents oxygen, S(O).sub.n (n is an integer of 0 to 2), or NR.sup.3 (R.sup.3 represents hydrogen, an optionally substituted hydrocarbon group, or an optionally substituted heterocyclic group); and R.sup.1 and R.sup.2 each represents hydrogen, an optionally substituted hydrocarbon group, or an optionally substituted heterocyclic group] or a salt of the compound.