Kyoichiro Yozakura

The eldest son of the Yozakura family and a gold-class spy, born on January 1st, 21 years old, with a height of 185 cm and blood type A. Known as "Kyoichiro Hirukawa" at the school attended by Taiyo and Mutsumi, he is recognized as a talented individual who became a vice-principal at a young age. Currently, this setting is somewhat ambiguous and is treated metafictionally by Nanao in the work.

Being the first child, he is the most talented in both combat and intelligence within the Yozakura family. He consistently ranks first in the "Male Spy Most Wanted to be Targeted by Female Spies" popularity poll, making him highly popular but equally despised by other spies.

Normally, he is a pleasant young man who always smiles, but he has an extreme sister complex, adoring Mutsumi to the point of considering anyone who gets close to her an enemy. This stems from trauma of not being able to protect Mutsumi from an incident in the past. However, his excessive sister complex makes Mutsumi feel creeped out and avoid him as much as possible, and he is disliked by Kengo and seen as a problematic person by his other siblings, including the eldest daughter, Futaba. Despite being a student council president in his school days, his approval rating was 0%, and he was nicknamed "Trash," "Scum," and "Worthless." He has a soft spot for small children, showing different sides of himself, such as being overwhelmed by the cuteness of a babyfied Taiyo or exhausting himself from being too selective when choosing a gift for Sui.

Although he overlooked Taiyo due to being Mutsumi's childhood friend, he has harbored strong distrust and resentment towards Taiyo since learning that "someone has been targeting Mutsumi for years." However, he also shows his senior spy side by advising Taiyo on the spy's code of conduct. Despite everything, he acknowledges Taiyo and Mutsumi as a "couple" and is genuinely willing to protect them.

He uses sharp steel wires called "Steel Spider" for combat, torturing enemies, and punishing Taiyo. Despite using spider-themed weapons, he dislikes spiders.

In Taiyo's silver spy promotion exam, he was the final examiner. He saw through Taiyo's true purpose of becoming a silver spy, unsettling him, but acknowledged Taiyo's determination after Taiyo awakened to "Myriad Blossoms" and slightly damaged "Goddess's Nest," leading to Taiyo's exam passing.

Later, he faced off against Hyaku and the former heads alone, defeating them all but was temporarily missing in front of Taiyo and others due to being poisoned by Tsubomi's blood, which was cured by Taiyo's "Myriad Blossoms."

In another manga by the same author, "Polo's Study Abroad," a different character named Kyoichiro Onimura appears.

His "Bloom" is "Void." The steel spider's threads spread on the ground after absorbing his blood, causing anything it touches to vanish without distinction. However, "Goddess's Nest" can neutralize this Bloom.

From episode 175 onwards, he becomes the principal of Teiou Academy.

He loves Mutsumi's children, Alfa and Hifumi, and sometimes empathizes with Hifumi's overly affectionate remarks. However, he occasionally finds himself being avoided by the two.