Gisou Kanojo

The protagonist, Mao Shinguji, is an apprentice exorcist monk whose profession is hunting demons. During the day, he lives a normal student life, but at the rest of the time, he devotes himself to his training at the temple where he lives. One night, Mao senses an unusual "demonic energy" in town and rushes to the scene, where he finds a seductive girl standing there completely naked. Her name is Luara, the "Princess of the Demon World Tree." She has come to the human world incognito to broaden her knowledge as the successor to support the demon world. [Translated from Official Website]