One of Toyosatomimi no Miko's palettes in the game resembles Sanae Kochiya, a boss/playable character debuting in Mountain of Faith. Another one of Miko's palettes also resembles Neku Sakuraba, a character from the game The World Ends With You
One of Koishi's alternate color schemes resembles that of her sister, Satori. Interestingly, inverting Koishi's default colors bears a striking resemblance to her sister's clothing as well. The same can also be done to their official artwork from Subterranean Animism.