Nezumi's dynamic with Bananya is pretty odd—he's basically always getting chased around before they inevitably patch things up and become friends again. The running gag is that he's perpetually starving, so Bananya-ko regularly feeds him to keep the peace.
What's interesting is that there's not actually just one Nezumi. The Bananya house is basically infested with an endless swarm of mice, all lurking around waiting for their next meal.
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