Suji Kim books in order
6 books in the catalogue, about 47 hours of reading in all; the shortest takes 6 hours and the longest 10 hours.
1 series and 3 standalone books in the catalogue.
Under the Oak Tree
4 books 1 Under the Oak Tree: The Novel, Volume 1 8.9 h 2 Under the Oak Tree: The Novel, Volume 2 7.6 h 3 Under the Oak Tree: The Novel, Volume 3 10.0 h
4 Under the Oak Tree: The Novel, Volume 4 length not known