Bouquet of Black Song Lilies is an item described in detail in Monster Girl Encyclopedia World Guide - Side III book.
Book Entry
These black song lilies are a flower that serves as the counterpart of Al Mar’s beautiful white song lilies.
This is also a beautiful bouquet, whose bewitching black petals are darker than the whirlpools of Dé Ryúa. A precious item that only grows on a location known as the solitary jet-black island!
These black song lilies, which symbolize impurity and corruption, wrap their mana around a monster that has received a man’s confession, and then in proportion to the pounding in the monster’s chest from being confessed to, brings about an obscene burning lust, transforming the confession’s romantic space into an erotic atmosphere with a scorching mood!
If you tie the knot with a monster using these, the mana possessed by the flowers promises the girl you love will direct her eternal lust at you!
Have fun with your song maiden every night, and propose to a Dé Ryúa song maiden for an eternal marriage!
~Hotel Dé Ryúa Casino Prize Flyer~[1]