Marshmallow, Imouto, Succubus

Marshmallow, Imouto, Succubus follows Kasuke Tsukikawa, a young man who discovers that his innocent younger sister, Saki, harbors a hidden succubus nature. As Saki’s dual personalities—her natural sweet self and her lustful succubus form—emerge, Kasuke must navigate the complex and forbidden desires that arise, especially under the influence of the moon’s phases.