Maou ni Natta node, Dungeon Tsukutte Jingai Musume to Honobono suru

Maou ni Natta node, Dungeon Tsukutte Jingai Musume to Honobono suru, A Demon Lord’s Tale: Dungeons, Monster Girls, and Heartwarming Bliss, I Became the Demon Lord so I Created a Dungeon and Spend Heartwarming Time There with Non-Human Girls, 마왕이 됐으므로 던전을 만들고 인외아가씨와 훈훈해진다, 魔王になったので、ダンジョン造って人外娘とほのぼのする, 魔王建造地下城转生到异世界建造人外娘

Before I realized, I had become the guardian of a dungeon, a Demon Lord. I was suddenly in a dangerous world with giant monsters loitering around, fighting for their existence, so I thought to go about developing the dungeon in order to not die but —- for some reason I was having quite the good time…. How did it turn out like this?

The protagonist, Yuki, having to live in that world now, uses his bold and sharp senses and spends time with a supreme dragon girl and a vampire girl; Sometimes laughing, sometimes being angry, passing days doing what he likes.