Ikoma

"So, how's life on Koutetsujou?"
Whenever this question is asked, regardless of what he's doing, Ikoma will immediately look up and talk passionately about the train of that other world. Where he grew up, trains are called "Hayajiro," meaning "forts that run like horses," whereas the stations situated along the railroad are called "Eki," referring to "places where horses rested in ancient times." According to Ikoma's enthusiastic descriptions, Koutetsujou is a pure black armored train with metal exterior. Although it merely belongs to a local daimyo, it is not any inferior to the shogunate's Hayajiro.
Ikoma wasn't born on Koutetsujou, but ever since boarding it to leave his Eki, he spent most of his time on the locomotive, developing a strong bond with the others aboard amid various crisis. His animated narration gives life to multiple people, such as the chubby Takumi who's also a mechanic, Ms. Ayame who's in charge of the train, Kurusu the guard, Yukina the driver, and Kajika, who takes care of the women and children. Of course, among them who feels most dear is Mumei, who's also presently aboard the Eternal. Even though she was the last passenger to board the Hayajiro, she still played a part in the stories of everyone else.
If you were to ask Ikoma about interesting stories of these people, one day would hardly be adequate to hear them all. As for details of Koutetsujou itself, they come naturally to Ikoma, a Hayajiro enthusiast; even tough times like wetting his shirt with cooled stove water to wipe his face can be told entertainingly. Evidently, he truly regards Koutetsujou as his home.
"...But Koutetsujou still can't be compared to the Eternal. After all, all of us frequently go hungry, and our weapons and equipment aren't as advanced as yours... If we had what you have, I'm sure we'd be able to live a better life."
Ikoma always sounds a little sad when discussing the differences between the two trains. He even told us crew about his family who died in an accident, the numerous destroyed Ekis, and the many companions he lost after boarding Koutetsujou... Carrying such remorse, he devoted himself to studying all sorts of knowledge and working hard, hoping to be able to turn things around with his own power if there were a chance to return to Koutetsujou.
"I have to be strong. My life is deeply enriched now, and Mumei looks happy to be on the Eternal too... This is all thanks to your help. I will do my best to share what I know about Kabanes and steam engines with you all. Hopefully, that will be of use!
"...Someday, we will return to Koutetsujou together. We will get our lands back from the Kabanes and plant tons and tons of food to feed everyone!"