Yoo offered his condolences to victims and his sympathy to those who have suffered, as he visited a local elementary school where displaced residents are staying, it said.
"I sincerely hope that relations between South Korea and Japan will improve," he was quoted as telling them. "I will try for that. I think that's what the people of both countries want."
It marked the envoy's first official trip out of Tokyo since taking up the post a week ago.
Seventy-two people were killed by the Aug. 20 disaster, with two others still missing, showed an official tally. Yoo also visited a peace memorial park in Hiroshima to commemorate atomic bomb victims, said the embassy. (Yonhap)