The Fight on Mt. Kageboshi is chapter five of the Hinowa ga Yuku! manga.
With Yomihime's first regiment was entirely wiped out by Hinata and her squad, Yomihime decides to take on the battlefield by herself even she manage to caught Soukai's army off guard by attacking the mountain flanks. Encountering Hinata, Yomihime thought that she already killed her long ago but it turns out Hinata reveals that she was the daughter of Hinowa, the person that Yomihime killed years ago. Tobari arrived to clash with Yomihime only to be parried effortlessly and with a single slash, manages to seriously wound Tobari.