| Akira Amatsume|
|First Appearance||(Anime) Episode 1|
|Portrayed By|| |
Akira Amatsume is one of the most important heroines in Yosuga no Sora. She is one of the most cute heroines of the series.
Having an innocent personality, Akira is much like an angel, she is the most lively of the heroines.
Because she lives at the local shrine, Akira spends much of her time practicing the habits and traditions of a miko (shrine maiden), including performance of requisite ceremonies and holiday festivals. It is heavily implied that she and Kazuha share the same father. Kazuha's mother does not like Akira because of this as she is a reminder of her husband's infidelity and she convinces her husband to disown Akira. Because of this antipathy, Akira is very submissive in her presence. Although Akira is not officially acknowledged, Kazuha's father keeps a distant eye on her, privately expressing pride in her at the shrine festival. Furthermore, Yahiro Ifukube, who helps look after Akira, admits to Haruka that her store is barely able to support herself let alone Akira, implying that Kazuha's father is also supporting Akira financially through Yahiro. At the conclusion of Akira's arc, she is told that Kazuha's mother and her mother shared a hospital room when the girls were born, that her mother died shortly thereafter and that Kazuha's mother saw Akira when she was a baby and liked her. Furthermore it is revealed that the pendant she thought was her mother's actually belonged to Kazuha's mother who was holding her after her mother died. The infant Akira pulled the pendant from around Kazuha's mother's neck and she was allowed to keep it so that Akira would have at least one memento from her dead mother. Akira has short brown hair and brown eyes.
- Mr.Migiwa (possible father)
- Ms.Amatsume (mother,deceased)
- Kazuha Migiwa (half-sister in the manga only)
- Mrs.Migiwa (step-mother,in the manga only)
- Yahiro Ifukube (Like an mother to her)
- She's one of two characters who've developed romantic feelings for someone but couldn't confess their love on account of speculation that their love interests might be biologicaly related and didn't want to commit incest.
- She's the only character in Yosuga no Sora to have been raised by a single mother.
- She's one of few characters to share a bath with their love interest.