Jellyfish Eyes

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 his new school. Like Masashi, the other students have strange creatures known as "friends" that adults cannot see.
(Source: Japanese = eiga.com || Translation = MDL)