In Kuro no Shoukanshi, Kelvin learns that he bartered away his memories in exchange for powerful new abilities in a new world, and that Melfina, a goddess is with him.
In Yofukashi no Uta, Kou stops going to school and begins slipping out to walk the streets at night, there he meets Nazuna, who ends up being a true vampire.
In Classroom of the Elite, Kiyotaka is a student of D-class, where the school dumps its inferior students and ridicule them. First, he does not care, until he meets Suzune and Kikyou.
In Isekai Ojisan, Yousuke fell into a coma for 17 years, now he is back, and his nephew Takafumi discovers that he lived in another world, speaks a strange language and knows magic.