After ending the battle against Zolgia, Basara regains his peaceful life with his two little sisters, Mio, the daughter of the previous demon lord, and Maria, her little sister who's also a succubus. As Basara pursues the preparations for the sports festival at school, one day he's attacked by a person being manipulated by magic. Recalling the strange gaze he felt at school, a suspicion of his begins to grow...
Quit complaining so much over 
adding a firework or two!
Jammer doch nicht so rum
wegen ’nem bisschen Feuerwerk!
¡¿Hasta cuándo te quejarás porque 
queremos un par de fuegos artificiales más?!
¡¿Hasta cuándo te quejarás porque 
queremos unos pocos fuegos artificiales más?!
C’est juste un feu d’artifice,
arrête de geindre !
Smettila di lamentarti così tanto
 soltanto per un paio di fuochi d'artificio in più!
Pare de reclamar tanto por conta
 de alguns fogos de artifício!
Хватит ныть, подумаешь, 
хотим один-два фейерверка добавить!