Short answers, pulled from the story.
Kouji Mori is a Japanese manga artist, born on the 28th of November 1966 in Tokyo, and the author of Holyland and Suicide Island. He was selected to supervise the completion of Berserk because he was the only person Kentaro Miura ever told the full story to before his death in 2021.
Mori and Miura met in high school and maintained a close friendship for the rest of Miura's life. The two co-authored a science fiction story early in their relationship and submitted it to Weekly Shonen Sunday, though it was never published. Miura later said their friendship inspired the relationship between Guts and Griffith in Berserk.
Kentaro Miura died in 2021 from an acute aortic dissection at the age of 54. Mori stepped forward to supervise the manga's completion, with support from publisher Hakusensha and Miura's assistants. The first volume under his supervision, volume 42, was published on the 29th of September 2023.
Mori's original works include Holyland (2000-2008), Suicide Island (2008-2016), Destroy and Revolution (2010-2016), Muhoto (2019-2022), Sosei no Taiga (2017-present), and D.Diver (2023-present). Most were serialized in Hakusensha's Young Animal magazine.
Mori stated he would only write episodes that Miura specifically described to him, and would not flesh out or invent material he does not clearly remember. He acknowledged the result would not be perfect, but said he believed he could tell the story Miura intended.
Berserk has continued publication in Hakusensha's Young Animal, the same magazine where it was originally serialized. Volume 42, the first under Mori's supervision, came out on the 29th of September 2023, and volume 43 was released on the 29th of August 2025.