The Gemini Vertex (ジェミニ・バーテックス), also known as a Futago Type is an enemy of humanity as well as the twelfth and thirteenth Vertex's the Hero Club encounters. It is based after the constellation Gemini the Twins.
- They appear as a humanoid in stocks with a very long beard that it used to attack when needed.
- Their running style resembles a monkey running in stocks.
The Dark Blue Gemini Twin was first introduced in Episode 5 of Yuki Yuna. After they defeated the first five vertex, Togo noticed the dark blue gemini twin was heading for the Shinju, as she tried to stop it Inubouzaki Itsuki went Mankai using her enhanced vine weapon to stop it and destroy the soul. The Pink Gemini Twin came in episode eight of overtime and Karin and Yuna then went to the vertex ad both punched it. It soon got back up but Fu used her new weapon from her new Spirit to bring it back down. Togo then shot its head then the girls went to seal it and the vertex has thousands of souls. Yuna shortly ends the battle with the power of her new spirit with hero kick filling her Mankai Gauge three flower petals.
- They do not rely on engaging the Heroes, instead relying on their extraordinary speed to dash towards the Shinju-sama.
- Due to their apparently low combat power, the Heroes tend to leave this Vertex alone and focus on the other Vertex that follow it, which is its original intention. They would only realize that it slipped past their defenses too late to perform adequate defensive measures.
- The Dark Blue Gemini Twin's soul is singular making it easy to defeat
- The Pink Gemini Twin's soul multiplies by thousands and it can only be defeated by an area attack like Yuna's Hero Kick