The mysterious legend manga genre in the United States has gained significant popularity due to its unique blend of fantasy, mystery, and adventure. These manga series often feature enigmatic characters, intricate storylines, and richly detailed artwork, which captivate readers and keep them engaged. The genre's appeal lies in its ability to transport readers to fantastical worlds while also offering thought-provoking themes and complex narratives.

One of the key reasons for the popularity of mysterious legend manga in the U.S. is the genre's ability to cater to a wide range of interests. According to a report by ICV2, the manga market in the U.S. has seen steady growth, with sales reaching $470 million in 2020. Mysterious legend manga, which includes popular series like "One Piece," "Naruto," and "Dragon Ball," accounts for a significant portion of this market. These series often have large fan bases and are frequently adapted into animated series, movies, and video games, further expanding their reach.

The appeal of mysterious legend manga can be attributed to several factors. Firstly, the genre's focus on complex characters and intricate storylines allows for deep character development and relatable themes. For instance, "Naruto" explores themes of friendship, perseverance, and the struggle for acceptance, which resonate with a wide audience. Additionally, the use of fantasy elements and mystical powers adds an element of excitement and wonder, making these series highly engaging.

Data from the Japan External Trade Organization (JETRO) indicates that the U.S. is the largest market for Japanese manga outside of Japan. This suggests that there is a strong demand for Japanese manga, including the mysterious legend genre, in the U.S. Furthermore, the manga industry in the U.S. has seen a rise in the number of manga conventions and events, which further highlights the genre's popularity.

Another reason for the success of mysterious legend manga in the U.S. is the genre's adaptability. Many of these series have been successfully adapted into animated series, which have gained widespread popularity. For example, "One Piece" and "Dragon Ball" have been adapted into long-running animated series that have been broadcasted on television and streamed online, reaching a broader audience.

In conclusion, the mysterious legend manga genre has become a significant part of the manga market in the United States due to its engaging storytelling, relatable themes, and adaptability. The genre's ability to captivate readers with its fantastical worlds and complex narratives has contributed to its popularity, making it a staple in the manga industry.