Railmin is blue with cyan arms, blue ring-shaped hands, 2 round, orange shoulders, a blue appendix, a cyan face and red markings.
For his Bugmin ego, see: Bug-Railmin
As a Bugmin, when he opens his mouth, his teeth are always shown.
Railmin is a happy Promin who loves trains. When Railmin makes a noise, he says 'Shinko' or 'Batao-Batao'. However, when Railmin sees or comes into contact with any of Zuzumin's droplets or anything like them, he says 'Unko' or 'Reishi' instead.
Railmin's Kamiwaza ability is to give anyone a train ride. As a Bugmin, he can set up a railway rollercoaster.
In the series
Railmin made his first camero appearance as a Bugmin in the beginning of episode 1.
Railmin's major role debut as a Bugmin was in episode 4 when he took both Wanda and Shuu on a railway rollercoaster. That was until Zuzumin stopped him with his droplets. Yuto then captures and debugs Bug-Railmin. Later, as his Promin-self, Railmin gave Yuto and his friends a train ride across the meadowy hills.
Railmin became Mirai's Promin buddy in episode 44 as Yuto passes him to her. Mirai uses Railmin to help her chase down Bug-Turbomin and Bug-Jetmin.
- Railmin is one of the first 6 Promins to be introduced in the teaser before the Kamiwaza Wanda franchise's debut.
- Railmin is one of the 4 Promins who became the Promin buddies of the 4 Kamiwaza Power-Shooters in the original Kamiwaza Wanda season. Railmin is Mirai's Promin buddy.
- Railmin resembles steam trains and subway trains.
- Railmin has a dislike on Zuzumin's droplets and anything like them.