Denji is a teenager who lives his life as a Devil Hunter.

Aiming to pay off the debt he inherited from his father, he starts hunting devils for the yakuza with his buddy Pochita, a "Chainsaw Devil", while living a tragically poor life.

Just when things seem like they couldn't get any worse, Denji gets betrayed and killed by the yakuza. As Denji starts passing out, he hears someone calling from inside his head...
My only regret would be 
leaving you on your own.
ستكون حسرتي الوحيدة هي تركك بمُفردك
Ich mach mir Sorgen,
was dann aus dir wird.
Si eso pasara,
mi única preocupación serías tú.
Lo único que me preocupa
es dejarte tirado.
Mon seul remords,
ce serait de te laisser seul.
Se succedesse, mi dispiacerebbe lasciarti da solo.
Meu único arrependimento
seria te deixar.
Ну и меня тревожит,
что оставлю тебя одного…