Ryuji Kurosaki

Ryuji Kurosaki (黒崎 竜司, Kurosaki Ryuuji) is the secretary of John Balks, mayor of Sakurami City. Ryuji is the holder of an Apprentice Diary, the "Secretary Diary".

History
Ryuji is seen accompanying John Balks whenever he is in his office. Ryuji assists Balks in connecting Kamado Ueshita's Server Diary to the HOLON III network, giving every citizen in Sakurami City an Apprentice Diary.

When Minene Uryu, Masumi Nishijima, Hinata Hino, Mao Nonosaka and Ouji Kosaka infiltrate the Quad Towers where John Balks and his two HOLON III terminals are located, Balks attempts to predict their Diaries with his own "The Watcher" diary. However, the five of them trick Balks' diary by writing in their own false entries, eluding Balks' security forces that were sent to capture them.

Ryuji proves himself to be handy at this moment. By using his "Secretary Diary", he can predict Balks' future actions regardless of the false entries. With this method, Balks eventually locates and traps Hinata, Mao and Kousaka, while other security forces ambush and kill Nishijima, with Minene losing a hand due to a claymore planted in advance.

Ryuji accompanies Balks into the Gasai Safe, a high-security safe in the building. He is later shot by John Balks for unwittingly giving away the keycode to the vault they were locked in, after Yukiteru Amano tricks his own diary to reveal his future capture and interrogation of Ryuji, which allowed Yuki to gain the keycode for the first door of the safe.