Poppy Pipopapo

Asuna Karino (仮野 明日那) is a registered nurse at Seito University Hospital and a personnel from the Ministry of Health. In reality, "Asuna" is a guise for her true identity known as Poppi Pipopapo (ポッピーピポパポ), a benevolent Bugster based on the character with the same name from DoReMiFa Beat, who acts as the "navigator" for the Kamen Riders.

Past
The mascot of Genm Corp.'s DoReMiFa Beat. While not much is known, Poppi Pipopapo was somehow modified around the time of Zero Day into becoming a navigator for the Kamen Riders. Given the ability to take physical form and enter the real world, she took the guise of "Asuna Karino" in order to blend in more easily.

Second Bugster Outbreak
Five years later, a second outbreak of the Bugster virus occurred. While Hiiro Kagami had been selected as CR's Rider, Asuna proposed a second candidate: a prodigious and anonymous gamer known only as "M". While Kyotaro Hinata seemed hesitant, he agreed that having another candidate was wise after the incident that cost Taiga Hanaya his job. He gave her a Gamer Driver and the Mighty Action X Gashat to give M should she find him, and gave her the orders to reopen CR.

Along the way, Asuna ran into Emu Hojo, a pediatrics intern chasing after his escaping patient. Asuna quickly realized that the patient, Sota Suyama, was experiencing symptoms of the game disease, a diagnosis that was confirmed shortly after. For the boy's sake, Asuna had Emu help bring Sota to CR. After touching base briefly with Haima Kagami, she left for Mighty Action X's press release in the hopes of finding M there, only to find Emu had brought Sota to the release. When she tried to take Sota back, the Bugster took over the boy's body, wrecking havoc on the conference. Asuna was forced to explain the Bugster virus to Emu, and told him about trying to find someone to use the Driver, not expecting that Emu would take it for himself. Much to her shock, Emu was not only compatible with the system and capable of becoming a Kamen Rider, but he had been M all along. After watching him defeat the Salty Bugster, Asuna finally showed him to CR, revealing her true form as Poppi and christening Emu as Kamen Rider Ex-Aid.

Personality
Poppi Pipopapo was created to serve as a guide to the riders in CR. She provides insight on the Bugster viruses, the Rider system, and helps to transfer patients to CR if the situation requires it.

Poppi's true personality is bubbly and energetic. As Asuna, however, she takes on a mature and no-nonsense persona, although her normal personality will momentarily surface if she is addressed by her real name. But there have been times when Poppi as Asuna reverts to her true personality on her own free will. Despite being based on a Vocaloid, ironically, it is revealed Poppi cannot sing very well without music to accompany her and causes distress to those around her when she does.

Arsenal

 * Two Energy Blades: As Poppi Pipopapo, she can turn a knife and a fork into energy blades that she can either attack an enemy with or break a Chocolate Block from the Mighty Action X Gashat to receive an Energy Item.
 * Teleportation: Like the Bugster executives, Poppi is capable of entering any level selected by the Kamen Riders.
 * Dance Influence: Poppi can influence Bugster Viruses into a rhythm dance.

Portrayal
Asuna Karino is portrayed by Ruka Matsuda (松田 るか), who previously portrayed Katsumi Sasahara in Kamen Rider Ghost: Ikkyu Eyecon! Awaken, My Quick Wit Power!!.

Etymology
In episode 12, Hiiro Kagami pointed out that her alias, Asuna Karino is simply a wordplay of "temporary nurse" (仮のナース). As Poppi Pipopapo, she is most likely named after the Hatsune Miku song, PoPiPo.