The comparison between the frequency distribution of superflares and solar flares. Filled circles indicate the occurrence frequency distribution of superflares on Sun-like stars (G-type main sequence stars with P
rot>10 days and 5,800<T
eff<6,300 K) derived from short-cadence data. Horizontal error bars represent the range of each energy bin. The definition of the vertical error bars is the same as Figure 3. Bold solid line represents the power-law frequency distribution of superflares on Sun-like stars taken from (Shibayama et al. 2013). Dashed lines indicate the power-law frequency distribution of solar flares observed in hard X-ray (Crosby et al. 1993), soft X-ray (Shimizu 1995), and EUV (Aschwanden et al. 2000). Occurrence frequency distributions of superflares on Sun-like stars and solar flares are roughly on the same power-law line with an index of −1.8 (thin solid line) for the wide energy range between 1024 and 1035 erg.