Rengoku is very eager with his duties and responsibilities as a Hashira and often comes across as cheerfully eccentric. He is amiable, pure of heart, and boasted extraordinary technique and swordsmanship stemming from strict practice and discipline. He is an honorable warrior who adhered to his code of morals and principles that was instilled into him by his mother at a young age; the most significant being his belief that those who were born strong have a duty to protect the weak.