12 : To You, Someday →

The episode establishes why Yuji is Mahito's natural enemy; as a vessel for Sukuna, Yuji is subconsciously aware of the soul's shape, allowing him to bypass Mahito’s defenses and strike his soul directly. Critical Reception Re-Watching Jujutsu Kaisen's First Season - Anime Rants

However, Mahito intervenes. In a brutal display of his technique, he transforms Junpei’s soul, turning him into a disfigured creature. Despite Yuji’s desperate pleas for Sukuna to heal his friend, both Sukuna and Mahito mock his helplessness, leaving Yuji to watch Junpei die in agony. Thematic Significance 12 : To You, Someday

The episode focuses on the tragic confrontation between and his new friend, Junpei Yoshino . Manipulated by the cursed spirit Mahito , Junpei attacks his own high school, seeking vengeance for the death of his mother. Yuji arrives to stop him, and for a brief moment, it appears he might successfully talk Junpei down, even inviting him to join Jujutsu High. The episode establishes why Yuji is Mahito's natural