Jujutsu Kaisen has progressively developed the multifaceted power system, and there are hardly any characters who reflect its development as Yuta Okkotsu does. Spoiler alert: This discussion covers significant manga events that occurred within the late Culling Game arc and the Shinjuku Showdown arc. Yuta’s abilities are closely tied to his vast cursed energy and his connection with Rika as he was introduced as a special grade sorcerer in Jujutsu Kaisen 0. Gradually, the series makes him one of the most powerful contemporary sorcerers, so the legitimization of the Domain Expansion is a major step.
Yes, in Chapter 249 of the manga, the story specifically confirms the Domain Expansion of Yuta Okkotsu. This declaration is made when he is fighting against Ryomen Sukuna in the Shinjuku Showdown arc when Yuta reveals a fully-actualized Domain labeling it Authentic Mutual Love. The moment confirms Yuta as having acquired the pinnacle of jujutsu mastery, as being equal to high level domain users in Jujutsu Kaisen. In this way, the manga proves speculation about his abilities that has long existed to be true.

The Domain Expansion of Yuta, Authentic Mutual Love (Shingan Sōai) is essentially connected with his Copy technique and his relationship with Rika. In contrast to traditional Domains which were centered around one natural technique, the Domain as Yuta perceives it is more of a large open field with infinite swords. All of these swords are cursed methods that Yuta has imitated and hoarded as part of the special malleability of his powers in Jujutsu Kaisen.
Activation of the Domain requires that Yuta aligns with Rika completely, usually through his ring as a channel of his power. As soon as it is deployed, the Domain generates a setting within which Yuta is free to utilize his copied techniques without the established restrictions. This mechanic sets his Domain apart since it is more focused on versatility instead of having just one overall impact.
The other feature of the Yuta's Domain is the sure-hit system, unlike the traditional fixed attacks. Rather than a guaranteed strike, which is set in stone, Yuta is allowed to choose a method among the swords in the Domain to act as the sure-hit effect. This flexibility enables him to customize his offense to the opponent, which is why his Domain is among the most tactically sophisticated in Jujutsu Kaisen.
Jujutsu Kaisen: mechanics and battle implementation of the Yuta's Domain.
In Jujutsu Kaisen, Yuta reveals the complete power of his Domain, when he faces Sukuna, who is considered by far the most powerful curse. In the Domain, Yuta employs methods like Jacob’s Ladder by Angel, which is a purification-based attack, capable of attacking cursed beings at the core level. In assigning this as the sure-hit effect, Yuta places Sukuna in the defensive stance, which points to the tactical depth of the Domain.
This Domain structure enables Yuta to create swords on command, each giving him access to a stored technique with the concomitant reduction in strain caused by copying. This system is a useful solution to one of the primary burden of his capability, to be able to strike fast and at a steady rate. Consequently, Jujutsu Kaisen represents his Domain as a resolution of his natural ability and his battle life.

Nevertheless, the Domain is not a free zone, and it can be maintained only with monumental cursed energy even by a special grade sorcerer. The Domain collapses following its use against Sukuna, which means that the process of prolonged activation is not sustainable. The limitation is in line with the larger guidelines in Jujutsu Kaisen where even the most powerful techniques have a heavy cost.
Thematically speaking, the Yuta's Domain represents his journey through Jujutsu Kaisen. The idea of Authentic Mutual Love is also connected to his relationship with Rika and inability to bond with others, but it has become his strength rather than a curse. This development highlights the repetitive theme in the series of transforming emotional weights into strength.
Finally, Jujutsu Kaisen makes it quite clear that the Domain Expansion of Yuta Okkotsu exists and is one of the most diverse and strategically difficult ones in the series. The Domain allows solidifying the role of Yuta as one of the most powerful characters with its unique mechanics, flexible sure-hit system, and narrative value. Combining technical innovation and thematic complexity, this series makes Yuta's Domain one of the key aspects of his character and the power system of the series.