Graphite

"Cultivate," - Graphite's catchphrase before transforming into his Bugster form.

Graphite (グラファイト Gurafaito) is one of the main antagonists from the series Kamen Rider Ex-Aid. He is one of the Bugster executives, along with Parado, who inserted a Proto Drago Knight Hunter Z gashat into himself, to be a Bugster of it. His main goal is to simply eliminate the human race. He is the Bugster who infected Saki Momose long ago.

He uses the Gashacon Bugvisor to infect people, mostly at the first part of the series. He is one of the High-Tier of the Bugsters, with Parado and Lovellica. He is portrayed by Shouma Machii.

Hiiro Kagami

"There is nothing I cannot cut," - Hiiro's catchphrase when wanting to cut something.

Hiiro Kagami (鏡 飛彩 Kagami Hiiro) is the secondary Rider of Kamen Rider Ex-Aid. He is a surgeon in Seito University Hospital, who is also the son of Haima Kagami. He uses the Taddle franchise gashats and a Gamer Driver to transform into Kamen Rider Brave. He is portrayed by Toshiki Seto.

Toki Meki Crisis

"Toki Meki Crisis! Gashat! Gachan! Buggle It Up! Dreaming Girl! Koi no Simulation! Otome wa itsumo Toki Meki Crisis!" - Toki Meki Crisis announcement sound.

Toki Meki Crisis (ときめきクライシス Toki Meki Kuraishisu) also translated as Heartbeat Crisis is one of the forms that Kamen Rider Ex-Aid provides. It is a dating simulation, and was from the Bugster Lovellica. The gashat is voiced by Ruka Matsuda. The suit is played by Jiro Uchikawa.

Poppy Pipopapo

"Costume Change!" - - Asuna transforming to Poppy, or vice versa.

Poppy Pipopapo (ポッピーピポパポ Poppī Pipopapo) is a character in Kamen Rider Ex-Aid. She is the Bugster from the game DoReMiFaBeat game. She is also Kamen Rider Poppy, where she uses the gashat Toki Meki Crisis, that was from Lovellica. 

Poppy as her other form, Asuna Karino, is a nurse for Seito University Hospital, and a personnel from the Ministry of Health. Poppy is also the singer of the theme song for Genm Corporation, People Game. Poppy is also part of the Mid Tier Bugster which includes her, Vernier, Kaiden and Gatton. She is portrayed by Ruka Matsuda as both Poppy and Asuna.