Hiyori Kusakabe
Hiyori Kusakabe is first shown as a co-worker of Kagami's at the Bistro La Salle . She was involved in the meteor crash seven years ago along with Tendou. Due to the accident, her parents were killed. She believed that they were murdered by a person wearing a Rider Belt, but after a period of uncertainty she concludes that Tendou, despite owning the belt, would never do something like that. After seeing Gatack wear another belt and discovering that he was Kagami, she also began to doubt him. In the end however, she decides to trust both of them as they have helped her so much. She carries a green crystal that originated from Area X, ground zero of the meteor crash. She seems to be able to talk with and read the emotions of inanimate objects, such as drawings and machines. She's quite clumsy and tends to zone out while working, resulting in complaints by customers. Later in the series, it was discovered that Hiyori is the child of a Native Worm who impersonated Tendou's mother down to her pregnancy, and later gave birth to Sisyra Worm, making her Tendou's younger sister.

The energy charge from the Hyper Zecter sent her along with the Souji Kusakabe to the edge of time and space. She returns to the real world to defend Dark Kabuto from Hyper Kabuto, stating that she no longer desires to live in the human world. Ultimately however, after a compelling speech by Tendou saying that she will not be hated in the human world, even though she is a Worm, she abandons Kusakabe Souji and returns to the human world. However, she is then attacked by Dark Kabuto. After being saved by Tendou, she returns to an almost normal life, and dreams of owning a restaurant come true. During the epilogue, she returns to her normal life in working at the Bistro, and now has Juka as a sister.

Juka Tendou
Juka Tendou is presented as Souji's young teenage sister, but in truth she seems to be his younger cousin. They were both taken in by their grandmother after the Shibuya meteorite crash. She's really close to Souj and tends to act the same way he does. She was injured in a car crash caused by Kamishiro, but blows it off to her brother's concern. She also assists her brother in running noodle carts across town. She has different ways of saying 'Good Morning' to Tendou and loves his cooking. Lately, she has been targeted by ZECT and the Worms. So far two Worms, disguised as Misaki and Daisuke, tried to either kidnap or kill her. She seems to be aware of the Zecters as the Kabuto, TheBee, and Drake Zecters fly around the entire Tendou household, while the Sasword Zecter crawls on the dining table. During the epilogue, it is shown that she has accepted Hiyori as her 'sister' and is now working with her at the Bistro La Selle.
A 8 year-old girl whom Kazama has accompanied, she seems to have amnesia but by episode 17, she slowly remembers time before she met Kazama Daisuke. She always completes Kazama's sentences for him. She is incredibly mature for her age, often taking initiatives which surprise even Tendou. In the end, after remembering her mother's face on the day that they were attacked at the bus by the same Worm that tried to kill her mother, she was finally reunited with her mother Junko. Drake killed the Worm, and Gon completely remembered her past but unfortunately forgot about Daisuke and treated him as a stranger. However, she regained her memories of being Gon while reading an article on Daisuke in a teen magazine. She helps Daisuke regain his Drake Zecter from his Worm imitation. She recently discovered the identities of the first five Riders, when they ganged up on Daisuke, who they believed was a Worm. In her latest appearance, she has given the Drake Grip to Tendou after stealing it from Daisuke. She returns to help both Daisuke and Rena with the Hopper Riders by spraying them with a fire extinguisher. When Rena gains her Worm memories, she is attacked by Rena. During the epilogue, she is still working with Daisuke. She also insists that she now be called Yuriko, not Gon.
A butler who serves the Kamishiro family, He serves Tsurugi and often acts as a parental figure to him. When the Kamishiro wealth is no more, but Jiiya hides this fact from Tsurugi. He tells Kagami about Kamishiro's sister and her death at the hands of the Scorpio Worm. He has a twin brother who keeps the Legendary White Knife. He knows that Scorpio Worm is Tsurugi's true form but has chosen not to tell him because Tsurugi, as the last of the famous British Discabil family, must, in one form or another, carry on its name. Jiiya is respected by Tendou who refers to him as 'Humanity's Treasure' due to his incredible skill as a chef. He has several students who hold him and high respect, and has published a cook book, which Tendou carries a copy of at all times. During the epilogue, it is revealed that he is the head cook for the Discabil Restaurant, which is owned by Misaki and named in his master's honor.
Yumiko Takemiya
Hiyori and Kagami's boss at Bistro La Salle, she seems to tolerate Hiyori's clumsiness and Kagami's tardiness. She sometimes requests Tendou to be her cook as he is a usual customer.
Series:  Kamen Rider Kabuto