TV-Series
Description
Akito Himenokōji is the male protagonist of his story, a sixteen-year-old high school student who has recently transferred to Saint Liliana Academy, where he is placed in class 2-A. His most defining background detail is that he and his twin sister, Akiko, were orphaned at a young age and subsequently separated for six years after being adopted by different families. Akito was taken in by the Takanomiya family, while his sister went to the Arisugawa family. Upon finally reuniting and arranging for them to live together, Akito hopes to resume a quiet, normal life with his sibling. However, a crucial secret complicates this goal: Akito was adopted by his former parents and therefore shares no blood relation with Akiko, a fact he has chosen to keep hidden from her.

Personality-wise, Akito is generally described as laid-back, level-headed, and hard-working, though he becomes exceptionally determined and responsible when a goal needs to be achieved. He is caring and kind, willing to go to great lengths for his sister and the people close to him. Despite being surrounded by multiple girls who express romantic interest in him, he typically maintains a calm and somewhat oblivious demeanor. He enjoys teasing his sister and watching others tease her, though he insists he only sees her as a sibling and strives to maintain appropriate boundaries in the face of her aggressive advances. While others frequently comment that he has a serious sister complex himself, he denies this interpretation of his protective feelings.

Akito's primary motivation is to protect his sister and preserve the secret of their non-biological relationship while supporting them both financially. To make a living for the household, he secretly writes popular erotic light novels centered on brother-sister incest, published under the pen name Kōichirō Shindo. He draws inspiration directly from his relationship with Akiko, even giving the characters in his stories names very similar to their own. In the story, his role is further expanded when he is given a fabricated student council position titled Vice-Assistant of Proxy of Secretary, which technically makes him the assistant to his sister, the student council secretary. This position was created largely to allow the female council members more time with him.

His key relationships are numerous and form the core of the narrative. With his sister Akiko, he shares a deep bond forged by their long separation. While he loves her and wants to live peacefully with her, he constantly works to deflect her extreme brother complex and romantic feelings, keeping their lack of blood relation a secret to maintain the status quo. With Arisa Takanomiya, the daughter of his adoptive family who considers herself his fiancée, he shares a sibling-like relationship. She eventually moves into his household to act as a manager. Ginbei Haruomi Sawatari is his childhood friend who transferred to his school to be near him. She harbors unspoken romantic feelings for him, though Akito typically regards her as his best normal friend. Anastasia Nasuhara, the student council vice-president, confessed to Akito on his first day of school. Their relationship is characterized by teasing and sarcasm, and she eventually lives with him as well, learning household chores from him. Arashi Nikaidō is the student council president and his cousin from before his adoption. She is aware of his secret and supports him, frequently making joking yet aggressive advances, referring to him as her underground lover. Finally, Kaoruko Jinno acts as his editor for his secret novel writing. She worries about his sister complex and tries to intervene, though Akito considers her a reliable friend.

Throughout the story, Akito does not undergo a dramatic personality shift, but his situation consistently challenges his efforts to maintain a calm, ordinary life. His primary development involves navigating the chaotic household he has unintentionally created while keeping his secret profession and his knowledge of his adoption hidden from his sister. In terms of abilities, Akito is a successful and talented novelist, able to support a household through his writing. He is also portrayed as being capable of taking care of a home and teaching others how to do household chores, a skill that contrasts with the wealthy and sheltered backgrounds of several girls who come to live with him.