Densetsu No Kokuou O Sagase!!伝説の国王をさがせ！！; Densetsu no Kokuou wo Sagase!!; Find the Legendary King

Set in a legendary kingdom, magic user Senri and his friends have been searching for a certain person. According to the instruction of the “crown,” that person is supposed to be in the universe below the palace. However…?! [Reverein Scanlations]