《天使心》之所以不能被視為《城市獵人》的直接續集，關鍵在於北条司從創作初衷上就刻意將它定位為「另一個世界的延伸」，而非時間線承接的後續故事。雖然冴羽獠、海坊主等熟悉角色再次登場，但他們所處的世界觀、人生走向與情感結局，早已與《城市獵人》本篇分岔，因此《天使心》更接近一個平行世界或替代時空的重新詮釋。

在世界觀設定上，《天使心》一開始便做出極具衝擊性的轉折——槙村香已在車禍中身亡，她的心臟被移植給來自台灣的少女李香瑩。這個前提本身就否定《城市獵人》中香與冴羽獠走向婚姻、迎向幸福結局的發展，因此兩部作品在時間線上無法銜接。北条司也曾明確表示，《天使心》並不是「香死後的正史續集」，而是一個「假如世界從一開始就不同」的故事起點。

隨著世界觀的轉換，作品整體風格也出現明顯變化。《城市獵人》以都市犯罪、槍戰動作與冴羽獠誇張的好色搞笑聞名，在輕快節奏中穿插英雄式的浪漫；相較之下，《天使心》的敘事重心明顯轉向親情、療癒與內在情感。故事核心不再是「獵人接案」的刺激冒險，而是圍繞著失去、替代、救贖與成長，描寫冴羽獠如何從一名孤獨的殺手，逐步學會成為一個父親般的存在。

角色設定的調整，也進一步凸顯這種「平行重構」的概念。李香瑩不只是香心臟的承載者，她本身就是一名受過嚴格訓練的殺手，背負沉重過去，並在與冴羽獠的相處中慢慢找回情感與自我。冴羽獠在《天使心》中淡化原本的搞笑好色形象，取而代之的是更多內斂、成熟與自責，這種轉變正是北条司想描寫的「另一種獠」。同樣地，海坊主在本作中獨自經營貓眼咖啡店，沒有與美樹發展戀人關係，而是收養了孤女美紀，展現出截然不同的人生選擇。

從創作者角度來看，北条司正是因為不想破壞《城市獵人》已經完成的美好結局，才選擇用平行世界的方式重用角色。他希望能在不受原作束縛的情況下，描寫「如果冴羽獠成為父親，會是什麼模樣」，也讓故事能從熱血與浪漫，轉向更貼近人生後半段的情感重量。這種創作自由，正是《天使心》存在的最大意義。

然而，這樣的選擇也導致讀者評價出現明顯分歧。許多《城市獵人》的忠實粉絲難以接受槙村香的死亡，以及世界觀被徹底翻轉，認為這種設定情感上過於殘酷；但也有讀者欣賞《天使心》更成熟、溫柔且富有療癒力的敘事，將其視為北条司人生階段轉變的投射。

總體而言，《天使心》並不是《城市獵人》的延續終章，而是一部建立在熟悉角色之上的平行故事。它保留了角色的靈魂，卻賦予他們不同的人生軌跡，是一次帶有情感實驗性的重構之作，而非單純為延續人氣而誕生的續集。

Angel Heart cannot be regarded as a direct sequel to City Hunter. Instead, it is closer to an extension set in a parallel world or an alternative timeline. Tsukasa Hojo deliberately repositioned familiar characters from City Hunter within a new worldview, shifting the overall tone from action-comedy to a more emotional, family-centered narrative. With Li Xiangying—whose heart once belonged to Kaori Makimura—as the central character, the story focuses on her growth and her father–daughter–like relationship with Ryo Saeba. Many background settings differ significantly from the original work, including Kaori’s death and the altered relationship between Umibozu and Miki.

From the perspective of worldbuilding, Angel Heart makes a decisive departure from the outset by establishing that Kaori Makimura died in a car accident and that her heart was transplanted into a Taiwanese girl, Li Xiangying. This premise fundamentally contradicts the ending of City Hunter, in which Kaori and Ryo marry and move toward a happy future. As a result, the two works cannot exist on the same timeline, and Angel Heart cannot be considered a canonical continuation of the original story.

This change in worldview is accompanied by a clear shift in narrative style. City Hunter is known for its mix of urban action, crime-solving, gunfights, and Ryo’s exaggerated comedic lechery, blending humor with heroic romance. In contrast, Angel Heart places far greater emphasis on family bonds, emotional healing, inner conflict, and personal growth. Rather than focusing on high-energy “hunter-for-hire” cases, the story explores themes of loss, substitution, redemption, and emotional connection, portraying how Ryo gradually learns to become a paternal figure instead of a lone assassin.

Character settings are also significantly reworked, reinforcing the idea of a parallel reinterpretation. Li Xiangying is not merely the recipient of Kaori’s heart; she is a trained assassin with a traumatic past, who slowly rediscovers her emotions and sense of self through her relationship with Ryo. Ryo himself is portrayed with a more restrained and mature personality, with much of his overt comedic behavior toned down and replaced by introspection, responsibility, and quiet grief. This transformation reflects Hojo’s intention to depict “another version of Ryo Saeba.” Likewise, Umibozu runs the Cat’s Eye Café alone in Angel Heart, without a romantic relationship with Miki, and instead adopts a young girl named Mei, further highlighting alternative life paths for familiar characters.

From the author’s standpoint, Tsukasa Hojo chose this parallel-world approach precisely because he did not want to undermine the completed and emotionally satisfying ending of City Hunter. By separating Angel Heart from the original canon, he gained the freedom to explore new themes—particularly what Ryo might be like as a father figure—without being constrained by established continuity. This creative flexibility is one of the core reasons Angel Heart exists as it does.

However, this decision also led to sharply divided reader reactions. Many long-time City Hunter fans found Kaori’s death and the drastic changes to the world setting difficult to accept on an emotional level, viewing them as too painful or disruptive. At the same time, other readers appreciated Angel Heart for its more mature, gentle, and emotionally resonant storytelling, seeing it as a reflection of Hojo’s own evolution as a creator.

In summary, Angel Heart is not the next chapter of City Hunter, but rather a parallel reinterpretation that borrows familiar characters while giving them different life trajectories. It preserves their emotional essence while reshaping their destinies, standing as an experimental and heartfelt reimagining rather than a conventional sequel.