Kyosuke volunteers to help Batsu and Hinata with their investigations into the attacks on students and the kidnapping of Batsu's mother. As the story unfolds it is revealed that Kyosuke is the one who kidnapped Batsu's mother under orders from his twin brother, Hyo Imawano. In the end, Kyosuke and his new friends defeat Hyo, while showing him the error of his ways.
When a new enemy emerges by the name of Kurow Kirishima and starts to wreak havoc among the local schools, Kyosuke and his friends set out to stop him. When his brother, Hyo, later appears and is possessed by the spirit of their father, Kyosuke reluctantly defeats him in combat resulting in Hyo's death. After this, Kyosuke disappears, leaving behind his friends who decide to quietly await his return.
"Mysterious Public Man"
Always cool, calm and collected, Kyosuke rarely shows much emotion. He is an intelligent and studious person who achieves high grades in all his subjects but excels at both mathematics and science. He has conflicting loyalties between his brother and his friends but ultimately wants what's best for both of them. He enjoys playing chess and shogi.
- Kyosuke lives by himself in a mansion near an unnamed college campus.
- In Project Justice, Kyosuke has been made Chairperson of the Taiyo High school's morals committee.
- He can play the saxophone.
- His last name, Kagami, can also be written as the Kanji character 鏡 which means 'mirror'.
- He is voiced by Isshin Chiba.
- Since Raizo is Hyo and Kyosuke's uncle, he is also Batsu's cousin.
- He makes an appearance in UDON's Street Fighter Legends: Sakura comic.
- He appears as a card in the Heroes and Heralds mode of Ultimate Marvel vs. Capcom 3.
- One of his super move in Capcom vs. SNK 2 includes Batsu and Hinata.