He rose to fame after portraying Arata Wataya in the Chihayafuru live-action trilogy in 2016, which earned him the 40th Japan Academy Newcomers of the Year Award in 2017.

[4] He has since portrayed characters in many other adaptations of popular manga series, including Okuyasu Nijimura in JoJo's Bizarre Adventure: Diamond Is Unbreakable Chapter I (2017), Sōta in Tokyo Ghoul S (2019), Yukishiro Enishi in Rurouni Kenshin: The Final (2021), Pegasus Seiya in Knights of the Zodiac, and Roronoa Zoro in the Netflix series One Piece (both 2023).

At the age of 15, Mackenyu watched a Japanese movie and the actor who starred in it inspired him to pursue acting professionally in Japan.

[8] Mackenyu landed his first feature film lead role in Take a Chance (2015) and was featured in an acclaimed short movie depicting a Japanese family suffering the aftermath of the World War II in Tadaima (2015) in which the movie won The Best Narrative Short in Philadelphia Asian American Film Festival.

[10] In 2013, Mackenyu turned his full attention to acting—including roles in the feature film Buzz (So-On: The Five Oyaji) (2014) and TV movie Yo nimo Kimyō na Monogatari (2014).

His fame grew dramatically in Japan after landing the role of Eiji Tomari/Kamen Rider Dark Drive/Paradox Roidmude in Kamen Rider Drive: Surprise Future; the film Tie-in to the 2014-2015 Entry in the Kamen franchise, Kamen Rider Drive, based on the popular series created by manga artist Shotaro Ishinomori[11] In 2015, he also landed his first lead roles in two USA film productions, Take a Chance (2015) and Tadaima (2015); for the latter he won a best supporting actor award at the Asians of Films festival.

[14] 2018 was a busy year with series Kiss That Kills and movies Chihayafuru Part III, manga-based Impossibility Defense and speed-drive action-drama Over Drive.

[19] In August 24 of the same year, it was reported by media outlets that Mackenyu's wife had given birth to their first child in Honolulu, Hawaii, in late July 2023.