As for traveling hours, the local train running the Takikawa Station - Kushiro Station section of the Nemuro Main Line (outbound trains only) takes exactly eight hours, making it the longest (the running distance is 308.4 km and it's the longest, excluding rapid trains).
運行時間では、根室本線の滝川駅～釧路駅間（下りのみ）の普通列車が8時間ちょうどで最も長い（運行距離は308.4km、快速を除外した場合には最長）。