Phoron Tatara’s no ordinary musician… as one of the rare Dantists who can summon elder spirits using music called Commandia, his gift is so strong that his spirit partner is none other than the infamous Corticarte Apa Lagranges. Sure, she may LOOK like a young girl in her human form, but you don’t get nicknames like “the Crimson Annihilator” and “the Bloody Duchess” for sitting back and watching the daisies grow. Now, at the behest of the Tsuge Divine Music Player Office, this dynamic duet travels the continent of Polyphonica on Phoron’s combination motorcycle/organ, following the song of the open road, orchestrating rescues and generally fixing whatever’s baroque! Some musicians wait for a muse to hit them, but Phoron makes his work for scale in POLYPHONICA!
Phoron Tatara and his spirit partner, the infamous Corticarte Apa Lagranges, walk through town, looking at the historic monuments as they wait for Phoron’s motorbike to be repaired. In a park, Phoron talks to a girl named Misaki who looked upset. She is unsure whether to retrieve a memento of her deceased grandmother from her old house. Phoron and Corticarte both encourage Misaki to retrieve it, neither knowing the danger this will put her in.
Phoron and Corticarte arrive at the Tsuge Divine Music Player Office where they meet Maura Ren, a woman being harassed by a peeping stranger. Or at least the spirit of a peeping stranger.
A new client comes to the Office with an interesting proposal. He needs an object retrieved from the bottom of the sea, his late father’s brief case, in the hopes that its contents will settle an inheritance dispute with his brother. The problem is that his brother has hired a rival divine song player.
The Yugiri twins reminisce over their father’s memento and the first time they met Phoron and Eufinley at the Torvas Divine Song Players Academy. Details about their pasts are revealed, along with the musical connection between Phoron and Corticarte.
Suzuna comes to the Office believing that her spirit has breached its contract and is working for another Dantist. Eufinley takes on the assignment of investigating the matter. It is clear that the spirit is visiting a Dantist with whom it formerly had a contract with. It is not immediately clear as to why.
The Tsuge Office becomes tense after a Eufinley receives a call from another Divine Music Player Office asking to have Rembart transferred to them. Phoron falls into a river and catches cold while on assignment. Eufinley sends Renbart to take over for Phoron while he recovers. Tempers flare between Perserte and Corticarte over who will care for the sick Phoron as the others worry if Renbart will leave.
An old school friend of Phoron, Yamuna, comes to visit and asks him for assistance. One day at work, Yamuna found a mysterious suitcase with a One-Man Orchestra. Since then he has been followed by an even more enigmatic man and little girl dressed in black.
Old memories of her past resurface when Prinesca finds a love letter in her school locker. Even though she is happy about the interest and encouraged by everyone in the office, she can’t shake her worried feelings. To make matters stranger, Corticarte also seems to have something troubling on her mind, too.
Phoron hasn’t been quite himself lately as his ability to play a Commandia has diminished. Corticarte is just as troubled by this development, but can’t seem to find a remedy. Eufinley suggests they visit the famous composer Zare to see if he can assist Phoron is getting through this rough patch.
The entire team is called to work on a case after Renbart’s is injured. Akatsuki and Mailreit are refusing to allow a burnt old house from being demolished. Phoron and Corticarte investigate the house, hoping to also learn the reason behind Akatsuki’s hatred of Mailreit.
The members of the Tsuge Office are called to assist a One-Man Orchestra developer, Terero Terumin, complete his work on a new invention. The Counterfeit Rainbow he is creating will play a Commandia on its own, without a Dantist. However, Terero is killed in an accident and his spirit helper, Krista, disappears. The situation becomes more complicated as the growing anti-spirit movement begins to stir up fear and animosity in the town.
Phoron and Corticarte try to convince Krista that her life will be in danger if she continues to sing for the Counterfeit Rainbow. The anti-spirit movement makes a serious misjudgment when their spirit bomb is accidentally set off. The powerful spirit encased inside is set loose and all lower level spirits go out of control and begin to cause mayhem. The team has to come together to prevent the wild spirits from destroying the entire town.