Tsume is depicted as a "a stereotypical angry anime loner" and an "emotionally distant hottie" who is confident, and at times arrogant, but keeps himself distant from his allies. Though he and Kiba continue to come into regular conflict, Tsume eventually comes to believe in their goal and becomes a loyal pack member. It is eventually revealed before moving to Freeze City, he had lived in another location with a large pack of wolves. Jaguara's wolf hunting troops attacked the pack, killing most of his family and friends. As Tsume attempted to flee from the battle, he was cast out by his pack and the alpha male attacked him, leaving Tsume with a large X-shaped scar across his chest. Tsume eventually traveled to Freeze City where his self-loathing over his actions caused him to refuse to befriend others.
Of all of the pack, he is closest to Toboe, whom he refers to as "runt." After the young wolf is accidentlly killed by Quent, Tsume cries over his body. Tsume is the last of the pack to remain standing with Kiba in the final battle with Darcia. He is killed after Darcia rips open his side and legs. Before dying, he whispers to Kiba that "we shall meet again.... in paradise." At the end of the series, Tsume is seen in his human form riding a motorcycle in a city.