Hyo appears as the final boss in all storylines if certain conditions are met. It is revealed that he is the true mastermind behind the attacks and kidnappings through the local schools and that he had been manipulating his uncle, Raizo Imawano, to do his bidding. His plan was to build an army of brainwashed students to reform and take over Japan and then eventually the rest of the world. After being defeated, his twin brother, Kyosuke, convinces him there must be a better way to change the world than through force. He eventually apologizes and reconciles with the rest of the cast.
With a new wave of attacks on the local schools caused by the Darkside Student Council of Justice High, who Hyo used to be associated with, Hyo had been captured and brainwashed by new antagonist Kurow Kirishima. However, after the cast defeats Kurow, Hyo reveals that he had been faking his submission the whole time. He then cuts Kurow down, leaving him critically injured. Each school's storyline then shows Hyo becoming possessed by the evil spirit of his late father, Mugen Imawano, and becoming Demon Hyo.
During the Taiyo High story, Hyo briefly regains his senses and pleads with Batsu and Kyosuke to kill him. After the fight, Hyo is freed from the spirit but dies due to his injuries which leaves his brother heartbroken.
Despite only being a high school student, Hyo is already a master swordsman. As well as being a part of the Imawano ninja clan, he used to be part of the "Reverse Society" who ordered the annihilation of the Imawano clan after he failed his mission. His cold and calculating demeanor seem to aid him and his political ambitions of reforming the country. Unbeknownst to him, he inherited his ambitions of world domination from his late father whose spirit was contained in the sword Hyo uses. Despite all this, he is shown to care for his twin brother at times who was the one who talked him down in the first game.
- Since Raizo is his and Kyosuke's uncle, that means Hyo is actually Batsu's cousin.
- Little to nothing is known about Hyo's personal or academic life except that he performed well in almost every subject and was the head of the student council.
- He has a talent for brainwashing people.
- In the Japanese version of Rival Schools, Hyo's white armband has "Seitou Kaichou" (生徒会長) written on it which means Student Council President. The armband is blank in the English versions. The writing appears in both versions of Project Justice.
- Some of Hyo's moves resemble Zero from the Mega Man X series.
- Hyo was voiced by Kaneto Shiozawa who sadly passed away during the production of Project Justice.
- Hyo is shown to drink wine in the School Life Mode of Nekketsu Seisyun Nikki 2 during Christmas Eve despite being a teenager.
- He appears as a card in SNK vs. Capcom: Card Fighters Clash.