Yozakura-sanchi no Daisakusen 22 (JUMP Comics DIGITAL)

Heiichiro, Hifumi, and Arufu arrive at an uninhabited island in the Arctic Ocean in search of Nanae! Nanakami has sealed himself up in a laboratory and is unable to leave.... They named the building "Nanakara Dungeon" and began a mission to rescue Nanakara...?

Heiichiro, Hifumi, and Arufu arrive at an uninhabited island in the Arctic Ocean in search of Nanae! Nanakami has sealed himself up in a laboratory and is unable to leave.... They named the building "Nanakara Dungeon" and began a mission to rescue Nanakara...?