Kotetsu is a glasses-wearing skinheaded teenager. As a member of Class Third, he wears a purple mantle. He uses a dagger as his weapon and is often using black magics.
Extra Chapter: "If Only..."Edit
Similar to the "What If..." scenario in Final Fantasy Type-0, the extra chapter is a parallel timeline where there is no war. The Akademeia is holding a school festival where the students from other schools, including the Militesi Academy, are coming to enjoy the event. Everyone survives in this timeline. Kurasame Susaya tricked Kotetsu and paired him up with Tono Mahorohi, a weird girl who is younger than him and hard to deal with.
Nagasone Kotetsu was a Japanese swordmaker of the early Edo period. Kotetsu worked as an armorer for some time, but later switched to swordmaking. His swords were known for their great strength and their ability to cut through helmets. However, Kotetsu's swords were often faked, and they were so well faked that even Kotetsu himself is said to have not been able to tell the difference.
"Ko" (虎) means "Tiger" while "Tetsu" (鉄) means "Iron". "虎" alone can also be pronounced "Tora". Literally, Kotetsu means "Tiger Iron" or "Iron of the Tiger" in Japanese.