At a total of 63 default and on-cartridge unlockable songs, Taiko no Tatsujin 3DS3's song list has been the biggest among the series' installments on Nintendo handhelds, and especially among those with random-encounter-RPG style story modes so far.
With that also comes a higher difficulty to include all of the songs into the story mode. In Don-chan's hunt for the Ryuumyakus/Dragonveins, for instance, there are way more songs set as boss-only songs and one-off challenges (especially collab songs) and not being put into random encounter on the enemy-ridden roads. But count it to the Taiko Team for managing to find a place for... only 62 of the songs?
In Seagal's (セガール) third contribution to Taiko no Tatsujin after Robot Rock 'n' Roll and Maigo no UFO, Diet Fighter drops the sci-fi facade and have vocalists Miyako Hagihara (萩原みやこ) and Ayuka Watanaba (渡辺あゆ香) sing about the struggles of dieting in swearing off all the tasty desserts and snacks. Yet after any decent playthrough of the game you might have noticed that this is the only default song to not be found in the 3DS3 story mode at all as other Donders have suggested.
The possible rationalizations for this is either it is put at a really obscure place such that no one was able to find it even after 9 months of release, or that it was a stashed mid-boss song for Lily at the museum or in Ancient Greece. The latter holds more water when Lily claimed must having extra-fudged desserts after multiple of her defeats, resonating the song's subject matter.
What do you think? Or have you already found the answer but was just withholding from the entire Donder community? Share with us below.