While Oshima experienced campus activism, showing objections against a security alliance and insists on the withdrawal of U.S. troops, he strongly continues to criticize authoritarian activities of the conventional left wing.
学生運動の経験もあり、安保反対・米軍撤退を主張しているが、既成の左翼の権力主義的な行動を激しく論難し続けた。