Kaze

Kaze and his older twin brother, Saizo, are members of a ninja clan from Igasato that has proudly served the Hoshidan royal family for several generations. Trained from a young age, Kaze became an exemplary ninja. Some time in their past, their father, Saizo the Fourth, was killed by Kotaro in an unexplained incident. His older brother became the new head of their clan, taking up the name Saizo. While Saizo was more vindictive in seeking retribution on his father's assailant, Kaze was more coolheaded. Still, Kaze pledged to support his brother to help him take down their father's killer. If Kaze achieves a S-Support, he will have a daughter named Midori with his spouse.

When he was little, Kaze accompanied Sumeragi and his subordinates during the trip to Nohr. One night, he spotted several suspicious Nohrian soldiers who were attempting to assassinate Sumeragi. However, he did not know what they were going to do and did not report the incident. Consequently, Sumeragi was killed and Corrin was kidnapped. Since that night, he felt that if he reported them, he might have prevented the tragedy. As a result, he promised himself not to pledge loyalty until he serves Corrin, and swore to protect Corrin to repent for his mistake. Kaze believes Mikoto may have foreseen her child's return and arranged things so that Kaze could fulfill this pledge.

(Source: Fire Emblem Wiki)