Pioneering work before becoming mainstream research

Various pioneering works in plasma physics in the last 30 years are reviewed. The following findings are discussed: 1) radial electric field shear in H-mode pedestal, 2) curvature of radial electric field and temperature profile, 3) intrinsic torque for plasma rotation, 4) hysteresis of flux-gradient relation in dynamic transport, 5) bifurcation of magnetic island states and 6) a trigger mechanism also known as a trigger problem for abrupt events. In the several years since the findings, some of these topics have already become mainstream research and others are state-of-the-art frontier research.