Macchan is a hybrid creature in the series, fusing feline traits with a matcha-flavored donut body. The name "Macchan" (まっちゃん) stems from "matcha" (まっちゃ), referencing the green tea donut component, aligning with the series' convention of blending food items with animal characteristics to create feline-confectionery fusions.

This character inhabits a post-apocalyptic Shinjuku ward in Tokyo, transformed into a desolate wasteland after an unexplained catastrophe eradicated human presence. Within these ruins, Macchan coexists with other hybrid entities like the donut cat Donyatsu and the bagel cat Begaru. Their narrative depicts everyday activities and playful interactions amid the decaying urban landscape.

Macchan appears across all 12 regular episodes and one additional special episode of the animated adaptation, totaling 13 episodes.