Chuji is a normal-looking rat who possesses light-colored fur and large round ears.
Wano Country Arc
Chuji accompanied its owner Some from the Flower Capital to Onigashima to provide entertainment for the Wano administration and Beasts Pirates' Fire Festival celebration. At some point, it became separated from Some, but she went out and found it in the hall and called it back over to her. However, their reunion was interrupted by Sanji kicking Queen's head into the floor. After Sanji kicked Queen out of the hall, he picked up Chuji and handed the rat to Some.
- The "chu" (忠 chū?) in its name means "loyalty", befitting its affection towards Some. But it may also be a reference to "chuchu" (チューチュー chūchū?), the Japanese onomonopeia for squeaking (like that of a rodent).
- The names of O-Some and Chuji may be reference to the historical novel Onna Kyōkaku – Komachi no O-Some (女侠客 小町のお染? "Chivalrous Woman – O-Some of Komachi") by Tamada Gyokushusai. The protagonist of the novel, O-Some of Komachi, is accompanied by a man called Kurofune Chuji (黒船忠治?), and acts as a type of chivalrous outlaw or gentleman thief.
- Sanji used to cook food for rats in his childhood, which was seen as proof that he retained his emotions and was a "failure" to the Vinsmoke Family. Coincidentally, Chuji appears at a moment where Sanji fears that he is losing his emotions, which causes the misunderstanding to be cleared.
- In addition, when Sanji handed Chuji over to Some, he remembered the time he feed rats as a child.
- One Piece Manga — Vol. 102 Chapter 1034 (p. 2, 11-13), Chuji makes its debut.
- One Piece Manga — Vol. 102 Chapter 1035 (p. 2-3).
- Onna Kyōkaku – Komachi no O-Some: Kokushokankai
- One Piece Manga — Vol. 84 Chapter 840 (p. 14-15).
- One Piece Manga — Vol. 83 Chapter 833 (p. 6).
- One Piece Manga — Vol. 85 Chapter 852 (p. 12).