某科学的宅电磁炮 某科学的九二八八 某科学的超电磁炮（这名字真的没打错……） 在起点网上搜吧，都是写得比较好的（特别是第一个）
不是妹妹，妹妹是美琴的克隆体，是官方为了提升一方通行提升能力等级制造出来的。简单点来说，就是生产出来被人杀的。
御坂美琴变成妹妹是第16集
姐妹 御坂妹妹们合力破坏了一方通行的绝招，美琴为了保护预御坂妹妹们和一方通行开始了战斗，倒下的当麻也在此时也站了起来。在当麻的特殊能力之下一方通行终于被打倒了。第二天，美琴和御坂妹妹在医院探访了受重伤的当麻。御坂妹妹们的去向仍然是个问题，美琴向当麻道了谢，随后美琴便跟随黑子回到了宿舍。
Miqin Okaka Becomes a Sister is Episode 16
Sister Yuzaka sisters together destroyed a side pass trick, Meiqin in order to protect pre-Yuzaka sisters and a side pass began to fight, the fallen when hemp also stood up at this time. Under the special ability of Dangma, one side of the passage was finally knocked down. The next day, Meiqin and Yuban sister in the hospital visited seriously injured Dangma. Yuban sister's whereabouts is still a problem, the United States Qin when Ma thanked, then the United States Qin followed the sunspot back to the dormitory.