A compound represented by the following General Formula (I), a tautomer or a stereoisomer of the compound, a pharmaceutically acceptable salt thereof, or a solvate thereof, is used as a voltage-dependent T-type calcium channel blocker: wherein A represents a 5-membered heteroaryl group or a fused ring of a 5-membered or 6-membered heterocyclic ring with a benzene ring or a pyridine ring, each of which may have a substituent; R represents a hydrogen atom or the like; B represents CR5(Q1) or NQ2, herein Q1 represents a benzimidazole group which may have a substituent, or the like; Q2 represents an alkyl group having 1 to 8 carbon atoms which may have a substituent, a heteroaryl group which may have a substituent, or the like; R0, R1, R2, R3, R4, and R5 each represent a hydrogen atom or the like; and n and m each represent 0, 1, or 2.