Fonogenico -- Negaigoto（ねがいごと）

Hyakki Yagyō from Wikipedia

Although I saw and enjoyed the first series of "Kimetsu no Yaiba"（鬼滅の刃）, I'm generally not one for supernatural horror or sorcery, but when doing my due diligence for this song, I discovered that it had been used as the theme for an NTV show based on a manga titled "Hyakki Yagyō Shou"（百鬼夜行抄...Excerpts from The Night Parade of One Hundred Demons） which was televised back in the late nights starting from February 2007.

From what I could glean from its synopsis, it's not so much about good battling evil between the physical and supernatural realms; it's more about different spheres of life so I gather that things are somewhat more peacefully enacted and contemplative. 

Certainly the ending theme for "Hyakki Yagyō Shou" reflects this feeling. A few months ago, I introduced a duo that had a run in the 2000s called Fonogenico and enjoyed their 2007 "Orange no Suna"（オレンジの砂）. Vocalist/lyricist Naoko Takayama（高山奈帆子）and keyboardist/composer Masaru Kawaguchi（川口潤）came up with this ending theme at the same time that the show aired called "Negaigoto" (What I Wish For) as the title track for their mini-album. It's a lovely piano pop ballad that almost sounds as if it could have come from a couple of decades previously. In fact, I like the song so much that I was surprised that the mini-album only hit a ranking of No. 259 on Oricon before it disappeared from sight. But then again, its attachment to a late-night niche drama and the observation that there may have been a lot of contemplative ballads being released at the time possibly nullified any impact.