Dungeon no Osananajimi

Van the warrior and Ryuka the dragon have been friends since childhood. As adults, Van is now a dashing adventurer, and Ryuka has become the big boss of a dangerous dungeon! Every time Van wants to hang out with his old friend, he must navigate a dungeon and clobber a coterie of Ryuka's monster underlings. Will their friendship grow into something more?

(Source: Seven Seas Entertainment)