Ichiko Oda, a high school student with medium-length brown hair and casual attire—often a pink hoodie layered over a dark top adorned with a small red-pink bow, paired with a dark blue pleated skirt—unknowingly adopts Cinnamon, a Shiba Inu harboring the reincarnated soul of Oda Nobunaga. Her kindness and patience define her daily life, tending to Cinnamon’s needs through walks, baths, and soothing belly rubs. Sharp intuition guides her actions, such as recognizing Cinnamon’s fascination with a shower cap and indulging his curiosity.

Though composed, she flusters over accidental underwear exposure or confusion about her name. She tolerates Cinnamon’s socially inept barking, attributing it to shyness, and contemplates the carefree existence of other dogs versus human anxieties. Her family includes a golf-loving businessman father and a mother distinguished by her "blinding bangs."

Ichiko’s gluttonous appetite occasionally results in winter weight gain. Defying others’ unease, she chose Cinnamon as a puppy, charmed by his intimidating appearance. Romantic feelings blossom for Hideto Mitsu, a Shiba-obsessed veterinary student, though she overlooks his fixation on Cinnamon and the historical parallel between Mitsu’s resemblance to Akechi Mitsuhide and Nobunaga’s betrayal. Interactions with Ai, a friend engrossed in male-male romance narratives, punctuate her social sphere.