Cagaster of an Insect Cage OST - Episode 1 Song (IN THE DARK)

Cagaster of an Insect Cage OST
Beautiful Piano Song and BEST Moment of the Episode 1 to me.
The name of the song is ...
I don't know it, but in the credits appear the song's name "Death or alive" of Hitomi Kuroishi.
I found a Piano Version on KZbin:
• Cagaster of an Insect ...
But I still haven't found the song in anywhere.
I think that the song is:
Hitomi Kuroishi - Death or Alive
because in the credits appear but I'm not sure
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