Cantarella

Cantarella: Haitoku no Ai to Doku no Hate
カンタレラ-背徳ノ愛ト毒ノ果テ-

Alternative

Cantarella: Kindan no Ai wa Doku to Naru
カンタレラ -禁断ノ愛ハ毒トナル-
novel

Based on Kurousa-P's popular Vocaloid song "Cantarella" and its subsequent musical adaptation.

Alternative

Hatsune Miku: Cantarella ~Poison of Blue~
Cantarella: Ao no Dokuyaku· カンタレラ -碧の毒薬-
manga

Cesare, the eldest child of the notorious Borgia household in fifteenth-century Italy, learns he has a sister he’s never met—Lucrezia. He is also given a poison called “Cantarella,” which has been handed down in the family for generations. The story unfolds after Cesare (here played by Kaito) meets Lucrezia (Hatsune Miku) for the first time… (Source: Seven Seas Entertainment)