Inspired by the responsibility, Nakano absorbed himself in trying to move the ZX-RR project forward - and claimed an emotional podium finish with third place at his and Kawasaki's home grand prix in Motegi.
Prior to the podium, Nakano had suffered a huge 200mph accident at Mugello when his rear tyre failed along the home straight - and proved there was a steely resolve behind his polite exterior by claiming seventh place just one week later at Catalunya.
Hopes were high that Team Green could build on its momentum in 2005, but the project seemed to have peaked and while Nakano claimed his third tenth-place championship ranking in a row, this time he was without a podium.
Nakano benefitted from Colin Edwards' last turn accident at Assen 2006 to claim MotoGP best second place, but unreliable machinery meant he was only 14th in the final championship standings. Kawasaki did all it could to convince Nakano to stay for 2007, but uncertainly over its new 800cc motorcycle - combined with the expected chance to fight for race wins on a Michelin-shod Konica Minolta Honda - tipped the balance in favour of pastures new.
Most riders would have done exactly the same, but the decision proved to be a nightmare: The new RC212V was uncompetitive (and remained that way for the non-factory riders) while Michelin lost its 'grip' in the battle for tyre supremacy with Bridgestone.
Nakano finished the year just 17th in the standings, with a best finish of tenth, but Honda believed he deserved a second chance and placed him back on Bridgestone tyres at the Gresini Honda team for 2008.
Shinya made a modest start to his Gresini career, with a best finish of eighth heading into round twelve at Brno, where he was surprisingly rewarded with a (valve-spring) factory Honda ride. HRC claimed that the move was down to his consistency (points at every round), experience and language - since he would be developing next year's satellite bike.
Few were convinced by that explanation - and Dani Pedrosa's subsequent switch to Bridgestone tyres seemed to indicate the real reason - but Nakano silenced the doubters by charging from twelfth to fourth on his factory RCV debut in the Czech Republic.
The final six races yielded a best finish of fifth, but Nakano knew that his Gresini seat was lost three rounds from the end of the season, when Toni Elias was confirmed alongside Alex de Angelis for 2009.
Nakano was tipped to become a Honda test rider, but was thrown a potential MotoGP lifeline when Kawasaki began pushing for their former rider to steer a possible third ZX-RR, to be run by 125 and 250cc team manager Jorge Martinez 'Aspar' next season.