长濑凑

比哥哥长濑准一小一岁的妹妹。家事、体育万能，可说是个完美的女孩子。言行举止很温和，平时也一直带着温柔的笑容，不过在对待孩子气的准一时却经常很严肃。 四岁起与父母“出外旅行”，在旅行的过程中习得了“全范围野外求生”，“军用徒手搏击”，“追踪／反追踪”，“全地形特种作战”，“兵器操作”，“侦搜与渗透”，“动物习性与沟通”，“高段刀法”…等等有趣的技巧，并在与优姬聊到当年旅行时说出“不够坚强的话，如果不让自己坚强起来就活不下去呢。”，后来返回日本与哥哥一起居住，发展出了“厨艺无敌”与“一碗拉面治感冒”这种特殊技能，TV版最后由父亲透露可能不是主角的亲妹妹，Ｘ计划当事人之一。

简介来自 Bangumi

She is Jun`ichi's younger sister. She is a year younger than he is and attends the same school that he does as a first year high school student. She is capable in all areas of household related work and is proud of it. She also has unique abilities, like listening to the ground to detect the presence of animals, as well as be able to communicate with them. She has feelings for Jun'ichi. She mentions that she was an adopted sister once, but later says it was a joke. Minato is blood-related to Jun'ichi in the PC game, in the PS2 version she is not related to him, and it is implied that she is not blood-related to Jun'ichi in the anime. She's a friend of Yocchan. In Hoshizora e Kakaru Hashi she visits Yamabiko with her. [From Wikipedia.]

简介来自 VNDB

主人公の1個下の妹。 凛々しい感じがするも、プリンやぬいぐるみなどが大好き。家事全般が得意で、スポーツなどもそつなくこなす。 ドライかつクールな態度をあまり崩すことはない。兄である準一と二人だけの時は多少穏やかになる。 「校内ではもう少し距離をとって欲しいから」

简介来自 Getchu