This castle site is better known for a piece of music than for its trees. Oita prefecture writes that the ruins of Oka castle are said to be the setting of Kojo no Tsuki, the song composed by Rentaro Taki, and a statue of him by the sculptor Fumio Asakura stands in the ninomaru enclosure. The cherry trees are Somei-yoshino, yamazakura and botan-zakura among others, about four hundred in all, with the peak from late March into early April.

Four hundred is a small number for this list.

Other entries on it run to three thousand trees in a garden and ten thousand around a lake. Oka appears alongside them with a fraction of that, which is a useful reminder that the hundred were never ranked by count. What is being recognised is a place, and the trees are part of it rather than the whole of it.

Here the order of things is reversed. At most sites the blossom is the reason people learn the name. At Oka the song came first for a great many visitors, then the walls, and the cherry trees are what they find when they arrive in spring. Four hundred trees inside a ruined enclosure on a plateau is a different experience from four hundred in a row, because the ground rises and falls and the flowers appear in separate pockets rather than in one continuous mass.