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.
The Horn Clan's patriarch will soon
 become my little sister.
Die Stammmutter des Horn-Clans
wird schon bald meine Schwester sein.
La matriarca del Cuerno
se convertirá en mi hermana menor.
La matriarca del Cuerno
se convertirá en mi hermana pequeña.
D’ici peu, la chef des Cornes
deviendra ma petite sœur.
La capofamiglia del Clan del Corno
 presto diventerà la mia sorellina.
A patriarca dos Chifres irá se tornar
minha irmã mais nova em breve.
Скоро старейшина Клана Рога 
станет моей младшей сестрой.