Ichiru Kiryuu

Zero's younger twin brother. When Zero and Ichiru were both younger, they were both taught and looked after by Touga Yagari. Ichiru did not seem to share Zero's natural ability because he had a weak body and would get sick quite often. Zero and Ichiru were very close as children, though Ichiru claims to have hated Zero after overhearing that his parents preferred Zero as a hunter.