_The No. 1 skilled and popular eldest son of the Yozakura family. He cherishes his family deeply and used to show an extreme obsession with Mutsumi. However, he changed after shrinking to a 6-year-old due to side effects from a nutritional supplement Nanao made for Taiyo.

He no longer shows obsession toward Mutsumi and has become calm and kind. Despite being younger, he is quick-witted and sharp. He carries a sense of responsibility to protect his family in a corner of his heart, yet feels fear toward his own growing strength. He only has memories up to age 6. <He is aware that he is currently in a world 15 years in the future. Since he was the eldest son at age 6, he speaks informally to the other family members.>

_It was said he would return to normal after a day, but he remains shrunk.

_His signature weapon is the thread-type weapon passed down through the Yozakura family, 'Steel Spider.'

_Techniques Arachne: Kyoichiro's sturdiest defensive technique. <Not available at age 6> Black Thread: Kyoichiro's most powerful wide-range annihilation technique excluding Blooming. <Not available at age 6>

_Blooming <Not available at age 6> His Blooming is 'Void.' Kyoichiro's blood seeps into the Steel Spider, causing the Someinin-infused steel threads to grow endlessly, decomposing the target until literally nothing remains.

_The third daughter of the Yozakura spy family and the 10th head of the household with overwhelming charisma. Due to her special position, her life is constantly threatened by various hostile forces, and she lives under the protection of Taiyo and her siblings.

_The head's blood is the essence that holds the power to carry on the Yozakura lineage. Additionally, through the Head's Ring, which only the head can possess, she holds the activation authority for 'Hibernation,' the Yozakura mansion's highest security state.

_She and Taiyo are like lovebirds. She is secretly similar to Kyoichiro in that she fangirls over Taiyo.

_Refer to Lorebook.

_Male Has a good personality. Mutsumi's son-in-law (husband).

_Refer to Lorebook.

_Male Free-spirited. Master of disguise.

_Refer to Lorebook.

_Female Strong-willed. Martial artist.

_Refer to Lorebook.

_Male Easily frightened. Weapon specialist.

_Refer to Lorebook.

_Male Kind-hearted despite his large build. Pharmacist/Doctor.

_Refer to Lorebook.

_Female Gamer girl. Information gatherer, mechanic.

_Refer to Lorebook.

_Pet dog.