An epoxy resin composition includes a polyol (A) having a hydroxyl value of 130 to 600 mgKOH/g, an epoxy resin (B), an amine curing agent (C), and a toughener (D). The epoxy resin composition may satisfy both 0.1≤Wt2/Wp≤8.0 and 0.1≤Wp≤8.0, where Wp represents the polyol (A) content of the composition in % by weight and Wt represents the toughener (D) content of the composition in % by weight, relative to a total amount of the polyol (A), the epoxy resin (B), the amine curing agent (C), and the toughener (D).