This reminds me of a manga I read in so far as it was also in the zombie apocalypse featuring a love triangle, except that one was BL and not GL, but same same different different.
Thinking about the conversion rate of rabbits to ruta, and the cost to gain citizenship, you'd only need like a few hundred rabbits to be a full citizen. Seems pretty easy to be honest.
I like that they provide some reason for the reset. Usually it just happens as a part of the premise. This makes it feel less like a rehashing of cliche and more like an attempt at a real story, despite the tropes still at play.