* First appearance: Battle 175

* Age: 18

* Type: Sei

* Type: Satsujin Ken

* Yomi Symbol: Ice

* Martial Art: Command Sambo

Boris Ivanov is a member of Yomi, a practitioner of Command Sambo, and the leading disciple of Alexander Gaider. He is the second Yomi member to fight Kenichi in a duel and is one of the first four Yomi members transferred to Kenichi's school.

Boris is usually seen in a military outfit due to his loyalty to his country and has a muscular build. His hair is silver and spiked in the back and usually has a small headband around his forehead. He was seen in a school uniform to fit in at Kenichi's school.

Being a Russian soldier and the right hand man to a colonel, Boris frequently acts in a militaristic manner. He strictly upholds orders and believes orders are absolute, as he will follow any order from his master or his teacher without question or hesitation. He also particularly hates anyone who disobeys orders, and seems jealous when he finds someone with greater loyalty than his. He seems to have a small degree of respect for anyone who is willing to speak against him openly.

Although he is an enemy of Kenichi, he will work with him to take down some opponents and find ways to listen to him, such as hearing Kenichi's words as advice and tips, not orders. He will also find loop holes to turn orders to his advantage without going against them.

Like Ethan, he was one of the few Yomi students to actually leave a good impression on most of the students their and held a respect for his teacher, Ono Kyouko, doing anything she asked without question and always did good deeds at his school. The teacher always thought of Boris as a very kind person, which may not be an overestimation, as he did ally with Kenichi to keep her safe from his own men due to loop holes he found, suggesting he may not be as bad as he seems and actually be more lenient towards Katsujin Ken.

He gets along well with his militia men as they follow him as soldiers and commander but doesn't seem to listen to Kanou Shou until he hears his master's orders first.

Boris is also the first opponent to acknowledge Kenichi for his strength, even to the point of even conceding that he is stronger.