A thirty-year-old Japanese man is transported to the country’s warring-states era and discovers he has not become a warrior or noble, but a small horse. Initially content to explore his strange new life, he intervenes when he sees a man being attacked by a bear. Saving the stranger changes his future completely, placing the reincarnated man into military service as a warhorse and giving him a front-row role in the history he expected to observe from the sidelines.