Yuuto's been sent to another world, where he is now commander, or "Patriarch" of a clan of warriors.  To survive in this new world, he uses his cell phone, his only connection to the girl he loves back home.
How about my little sister, then?
Wie wär’s dann mit meiner Schwester?
Entonces, ¿qué tal mi hermana menor?
Entonces, ¿qué tal mi hermana pequeña?
Que dirais-tu de devenir
ma petite sœur, alors ?
E se diventassi la mia sorellina?
O que acha de ser minha
irmã mais nova então?
Может, тогда младшей сестрой?