Mackenyu (新田 真剣佑, born November 16, 1996) is a Japanese actor born in Los Angeles, California. He is the son of actor and martial artist Sonny Chiba. He attended Beverly Hills High School in their Advanced Placement Program and appeared in a few films and TV shows while growing up. As a young child, Mackenyu had many interests including horseback riding, Yabusame, Kyokushin Karate (he was placed third at the US Kyokushin Karate Nationals), gymnastics, water polo, and wrestling (for which he became the school representative). He was also into music, playing piano since he was 10 years old, and later participated in the brass band of his high school in Beverly Hills, playing saxophone, and flute.

At the age of 15, Mackenyu watched a movie of Haruma Miura and got inspired to pursue acting professionally in Japan. He held on to the dream of co-starring with the actor once he established his career, which then came true in the movie adaptation of Gunjō Senki (2021). Mackenyu landed his first feature film lead role in Take a Chance (2015) and was featured in the acclaimed short movie Tadaima (2015) for which he won a best supporting actor award at the Asians of Films festival. He moved to Japan later in the same year.