WHAT: "An elementary school student named Masashi finds flat cardboard boxes at a home in which he just moved in. A strange creature like jellyfish comes from the cardboard. Masashi names the strange, but cute creature "Kurage Bo" and they become friends. Masashi places Kurage Bo in a bag and takes the creature with him to school his new school. The other students and adults can not see Kurage Bo." (via)
JELLYFISH EYES ("めめめのくらげ") is a film directed by Takashi Murakami, created by Kaikai Kiki. And while I've posted a teaser trailer before #onTOYSREVIL, the movie has since been released, and posted here is the 101-minutes film (in separate YouTube videos), with English subtitles! Official website @ www.jellyfisheyesthemovie.com + details on Wikipedia.
Trailer (with English Subs):