Eastern Japanese Toad (Bufo formosus)

This species has been split - given the location, this is most likely an Eastern-Japanese Common Toad B. formosus (although Western-Japanese Common Toad B. praetextatus/japonicus sensu stricto - both names refer to the same species - isn't impossible as it's been introduced to parts of Japan other than its native range)

@DaLilFishie oh interesting. I didn't know a proper study had been done since there were suggestions of this many years ago.
I just found the paper which splits them, from 2023:
Population genetic structure and hybrid zone analyses for species delimitation in the Japanese toad (Bufo japonicus) - PMC