Pochita is a high school boy who mysteriously transforms into a golden-yellow Akita Inu puppy with a curled tail. Before this change, he was a loner, solely interested in gardening, with only one friend, Usagi Tsukishiro, who sometimes teased him. He secretly admired classmate Karen Inukai but lacked the confidence to tell her. After his transformation, Inukai finds him in the rain, takes him home, names him Pochita, and becomes his owner. Initially distressed, he yearns to return to human form and his family, but becomes conflicted by the affectionate attention from Inukai, whom he previously idolized.

Living solely as Inukai's pet dog at first, Pochita navigates daily routines like walks, baths, and household life. His human consciousness leads to frequent unintended intimate situations: during walks, he is forced into canine-level perspectives like viewing up Inukai's skirt; during baths, his gaze instinctively averts from her nakedness. He attempts to convey complex human emotions, barking "I love you" despite knowing Inukai cannot understand. Efforts to seek help from others, like Inukai's dog-fearing friend Mike Nekotani, are complicated until he helps her during a centipede encounter, building trust and slightly easing her phobia.

Pochita later gains the ability to shift between dog and human forms. This duality adds complexity to his relationships: he experiences life as Inukai's devoted pet while reconnecting with his human world. Interactions with Mike shift from mutual apprehension to cautious tolerance, especially after incidents like her changing clothes near him, provoking Inukai's jealousy. His relationship with Usagi resurfaces, complicated by her lingering feelings and scenarios like her appearing in provocative costumes. He remains psychologically torn between embracing the comfort of Inukai's affection as a dog and pursuing normalcy as a human.

His background as an isolated gardening enthusiast fuels his initial passivity and inner conflict. The ongoing tension between his human identity and canine experiences shapes his character arc, marked by gradual adaptation to his dual existence rather than a resolution of his predicament.