>>1286308In terms of Japanese HSR the timeline goes something like this.
The JGR C51 Class was the first foray into higher speed rail.
After that would be the Asia Express Pashina Class for the southern Manchurian railroad. Then what followed would be the JNR C62 class that took over the Tsubame services in mainland Japan. What followed would be the private company Odakyu with their 3000 series being the actual direct predecessor to the shinkansen. Afterwards JNR expermiented with their 151 series EMU and eventually the idea that using EMUs for high speed rail was feasible we got the 0 Series we all love and know today.
Pic related the shinkansen could of ended up as a super aesthetic Hudson whyte steam loco.