While out on their rounds one day, Tsugumi and Hisui learn of the existance of a book written by a prostitute from Yokohama's redlight district. Hisui seems especially desperate to get his hands on this book and when Tsugumi learns the reason why she becomes determined to help him. When Tsugumi discovers that Shiginuma Shouko, wife of the shady owner of the Nachtigal dance hall, she finds herself stepping back into potentially dangerous territory alone.
They're a brilliant, thrilling 
harmony of salty and sweet.
.إنّها تملك انسجامًا رائعًا وشيّقًا بين الملح والحلاوة
Die brillante und aufregende Harmonie
zwischen Salz und Süße.
Brillan y son la armonía
de lo salado y lo dulce.
Brillan y son la armonía
de lo salado y lo dulce.
L’harmonie entre sucré et salé
est si palpitante et glorieuse.
Il dolce e il salato si sposano 
in maniera eccellente ed eccitante.
São uma brilhante e emocionante
harmonia entre sal e açúcar.
Превосходная и волнующая
гармония соли и сахара.