異世界ねぇちゃんは、イク時しか魔法を使えない

"Why does this feel so good? What magic did you use?!" His childhood friend knows nothing of sex, but that doesn't stop him making her come over and over again... Allow me to teach you everything while you melt around me! (Source: Coolmic) Note: Originally serialized as 9 ‘episodes’, and later released as 3 chapters.