Well well, look like that story idol sibling, the older one not really popular and the younger is popular “forgot the title, and in the same time it also like Seiyuu Radio no Ura Omote. Interesting.
She is succubus, and she said thing like there is also other succuby, in the genre it said drama too, well i think there will be a chance that 3rd wheeling char will appear soon. I hope MC not that easily to fall in love with other succuby.