... nor in the West, to be fair. Lies and cheats are commonplace in any Western workplace.

I think you are over-generalizing. Self-reliance is big in Japan too, even while egoism is not - it's drilled into people basically from birth, with things like students cleaning their own schools. Innocence is always politely expected until openly questioned, at which point it turns almost automatically into guilt; but it doesn't mean it's not "foundational" - in fact, it's much more entrenched, it's just that the act of questioning it carries so much more weight on all sides (an unfair accusation, if determined, would be extremely shameful) that nobody wants to go there until absolutely necessary.

They just play the game with a slightly different set of practical rules.