The reaction-boosting timeline is, roughly, this:
During teh food riots, Sam saves his Japanese boss from rioters by blazing away with his gun then, when he's out of ammo, grabs a katana and hacks a path through the crowd, saving his boss. Later interviews have him credit the swordplay to his practice of Kenjutsu and his personal belief in the samurai tradition. The media takes this for a ride and a wave of nationalism spreads.
Move-by-Wire is adapted from avionics, putting the body into constant siezure, but allowing for astoundingly fluid movement when put into action. Most test subjects die, and no one can figure out why. (My Essence, noooo...)
Sam winds up moving up in his corporation (Shiawase, a sit turns out) and even starts romancing an exec's daughter. His prime rival doesn't like teh idea of "tainting" a "noble Japanese bloodline" with dirty gaijin blood, even if he has a samurai's soul.
Shenanigans.
With his boss dead and evidence found that Sam did it, his rival has him arrested. He *should* be put to death (And is forbidden from honorable suicide!), but his GF begs for his life and he is instead put into the experimental reflex program. If he dies, good, if he lives, science! Either way's a win.
Sam manages to adapt to the proceedure better than most (It being an experimental version not quite as Essence-pounding) and manages to not only survive, but thrive.
More shennanigans.
Shiawase's home office comes in after the bloodshed, arrests what's left of RIval-San, gathers up the data, and declares the whole thing a wash. They spend a decade or more, bringing the Move-by--Wire system down from a IV to a III to a II to a I, eventually managing to create Wired Reflexes that are similar, but different, and even manage to create a "reflex trigger" that allows the user to shut them off an dlive a normal life, rather than being all-fast, all-the-time.
Sam has never been (officially) found. Rival-San has never been heard from again. Wired Reflexes become a smash hit, and later MbW is released, despite being an older system, finally in a state where most people don't instantly die from the Essence hit.
So, the whole thing is effectively built *backwards*, with the highest-end cyber being first, then slowly the engineers cut off parts, cut corners, and managed to find cheaper ways of getting things done. Sort of like how a Xerox machine used to cost ten grand, but today you can buy a printer-scanner-copier for your PC for under $40.
