The Book liner notes. Ayase – songwriter, producer Ikura – vocals Takeruru – guitar Mayo Hoshino – based story writer Takayuki Saitō – vocal recording Masahiko Fukui – mixing Niina Ai – music video animation, cover artwork design Charts Weekly charts Year-end charts Certifications Release history See also List of Hot 100 number-one singles of 2020 (Japan) References External links Thanatos no Yūwaku on Monogatary An Invitation from Thanatos on the official website 2019 debut singles 2019 songs Billboard Japan Hot 100 number-one singles Internet memes introduced in 2020 Japanese-language songs Songs about nights Songs about suicide Sony Music Entertainment Japan singles Viral videos Yoasobi songs