Due to very bizarre circumstances, the human boy, Suzuki Iruma, ends up in the netherworld. He is keeping the fact that he is human a secret and attends the Demon School Babyls. Because he is human, he cannot use magic so he had been using the Gluttonous Feeder Ring to get by in school. But then one day, the ring started to speak! Why, though? Iruma then meets the incarnation of the ring who calls themselves Alicred, AKA Ali-san.
Get your demongos! 
Every last one's gotta go!
!اشتروا المانغا الشّيطانيّة! يجب أن تباع جميعًا
Direkt vom bösen Mango-Markt!
Verkauf zum Schleuderpreis!
¡Vendo demomangos!
¡Tengo pocas unidades!
¡Vendo demomangos!
¡Vamos, hay poquitos!
Les meilleures malmangues du marché !
C’est cadeau, à ce prix !
I migliori demongo della regione!
 Demongo per tutti i gusti!
Pegue as suas mangas diabólicas!
Preciso vender todas!
Покупайте мои деманго!
Все до последнего их забирайте!