It's part of a thin book series by the circle Metamor, artist Ryo, called "Juugun Ian Kan Akagi" (Comfort Ship Akagi). It's sequels are "... Kai", "... San", and "... Yon". After "Kai" is a standalone volume in the same continuity called "Reebe-kun no Usui Hon" (Sketchy Lebe Book) which contains the scene in question.
It's part of a thin book series by the circle Metamor, artist Ryo, called "Juugun Ian Kan Akagi" (Comfort Ship Akagi). It's sequels are "... Kai", "... San", and "... Yon". After "Kai" is a standalone volume in the same continuity called "Reebe-kun no Usui Hon" (Sketchy Lebe Book) which contains the scene in question.