Arc 1Thunder and Vengeance
After a demon killed his parents, Uesugi Sasuke used the Sasuke Template System to hunt demons and gain powerful techniques. He trained under Jigoro Kuwajima, awakened the Sharingan, and mastered a controlled Chidori, but Kuwajima challenged him to find something worth protecting as Sasuke continued training alongside Zenitsu Agatsuma.
- Uesugi Sasuke found a gray-skinned demon devouring his father, and after it nearly killed him, his hatred awakened the Sasuke Template System and healed his injuries.
- Uesugi Sasuke escaped the demon, buried his parents, and swore revenge before the system sent him to hunt three lone demons for revenge points.
- Uesugi Sasuke killed demons to unlock the Great Fireball Technique and Chidori, then injured himself when Chidori’s speed carried him toward a cliff.
- Uesugi Sasuke traveled to Mount Momoyama and persuaded Jigoro Kuwajima to teach him Thunder Breathing after demonstrating his dangerous lightning power.
- Uesugi Sasuke struggled with swordsmanship and Thunder Breathing while training alongside Zenitsu Agatsuma, then combined breathing with chakra to awaken the One-Tomoe Sharingan.
- Uesugi Sasuke used his Sharingan to learn Thunder Breathing’s opening stance and control Chidori, piercing a boulder without losing control.
- Jigoro Kuwajima challenged Uesugi Sasuke to find something to protect and ordered him to swing his sword a thousand times each day.
- Uesugi Sasuke sparred with Zenitsu Agatsuma, who suddenly used Thunderclap and Flash before collapsing unconscious, leaving Sasuke wondering about his hidden power.