放課後の迷宮冒険者～日本と異世界を行き来できるようになった僕はレベルアップに勤しみます～•Houkago no Dungeon Diver: Nihon to Isekai wo Ikiki Dekiru You ni Natta Boku wa Level Up ni Isoshimimasu

Dragonnap

Yu Jitae is a Regressor wielding limitless power—and he still isn't strong enough to prevent the end of the world. Because four bored, young dragons once descended to Earth for fun, Yu has been caught in an endless cycle of failing to stop the apocalypse. But this time, in yet another timeline, Yu decides to try something different: maybe he can nurture the destruction out of these dragons as their guardian!<br><br>(Source: Tapas)