Hei He
English title: Undetectable Box
Japanese title: 黑盒
Alternative titles: Black Box
Type: ONA
Source: Original
Episodes: 1
Status: Finished Airing
Aired: Jun 26, 2019
Duration: 12 min
Rating: PG-13 - Teens 13 or older
Studios: 717 Animation Studio
Genres: Action, Suspense
Themes: Psychological

I often fall into the fantasy upon her back. What kind of person is she? What does she like? What world view does she hold? From the occasional detailed observations of her daily life, I have inferred many unexplainable clues... After a series of fantastic imagination, I suddenly realized that the girl who has been dialoging with me in my mind is just my own wishful thinking. Therefore, on the day of the reunion, I decided to take this step...

(Source: YouTube)