Sanemi Shinazugawa is a major supporting character of Demon Slayer: Kimetsu no Yaiba. He is a Demon Slayer of the Demon Slayer Corps and the current Wind Hashira.
Sanemi is also the older brother of Genya Shinazugawa, a Demon Slayer who fought alongside Tanjiro Kamado and Nezuko Kamado. Before becoming a Hashira, Sanemi, along with his partner Masachika Kumeno, defeated the former Lower Rank One, Ubume, with Masachika dying as a result.
Being one of the strongest Hashira, Sanemi’s sword matches his appearance. His sword is very durable and lasts throughout the series. It had no problem piercing through the box that Nezuko is held in. He fought against Kokushibo during the final arc of the manga. His sword was able to clash with the demon’s blade and not waver or break during this battle. Kokushibo is the second most powerful demon and his sword is more durable and sharper than a normal nichirin sword.
However, Sanemi doesn’t necessarily need a nichirin sword to take out demons. Before becoming a demon slayer, he hunted them on his own by incapacitating them and holding them down until daybreak.
Master Swordsman: Being a Hashira of the Demon Slayer Corps, Sanemi is one of the most powerful and skilled swordsman in the entire organization. His swordsmanship proficiency matched that of Giyu Tomioka's, an extremely skilled swordsman in his own right, during their sparring match while undergoing pillar training. Sanemi's skills with the sword allowed him to keep up with and impress Upper Rank One, Kokushibo, a demon with centuries of swordsmanship skill under his belt. Sanemi could also adapt and work with Gyomei's Stone Breathing techniques to push back Kokushibo.
Wind Breathing: A Breathing Style that Sanemi learned and mastered with Masachika Kumeno after tutelage from an unknown cultivator. As the Wind Hashira, Sanemi considered to be the most skilled Wind Breathing user of his generation. His level of skill with Wind Breathing reminded Kokushibo of the first Wind Hashira during the Sengoku Era, the golden age of Demon Slayers.
Standard Nichirin Sword: As a Demon Slayer, Sanemi carries around a standard sized and shaped Nichirin katana with a jagged pattern resembling the jaw of a beast in a shade of green. His hilt is in an abstract shape with 8 points with an overlapping pattern; each plate has a forest green core with a silver border. As a Hashira, Sanemi's blade has the words Destroy Demons engraved on the side. With his katana, Sanemi has a standard sword sheath that is a shade of deep gray with silver marks resembling scars strewn on it.