He is the best known dubbing roles for Mel Gibson, Harrison Ford, Chow Yun-fat, Peter Weller, Tim Allen, Sean Bean, Choi Min-sik, Stringfellow Hawke (Airwolf) and many more.
After graduating from junior college, Isobe joined the Haiyuza Theatre Company in 1972, where he gained experience on stage under director Koreya Senda, mainly in Shakespeare's plays, which were well received.
Later, he played the role of Shishiōin, the nemesis of the main character, Kirigakure Saizō, in NHK's drama Fūjin no Mon.
Since then, he has played roles in many stage, television, animation, and film productions in both period and contemporary dramas, and left Haiyuza in 1989.
He originally dubbed Heston when he filled in for Naya in the Friday first-run showing of The Naked Jungle, and has since served in three new recordings.