Jellyfish

Masashi and his mother Yasuko relocate to a quiet suburb and begin life in a new apartment. Masashi feels deep sadness over his father's death, but tries to remain cheerful for his mother. In the unfamiliar room, he senses a mysterious presence that hints at hidden things to come.

The day after moving, Masashi meets a jellyfish-like creature while returning from visits to the new elementary school. He names it Kurage-bo and learns that it adores chee-kama. The unlikely pair instantly bonds, even though they share no common language.

Masashi hides Kurage-bo in his backpack as he goes to class. He discovers that every classmate has a F.R.I.E.N.D. and a glowing Device to summon them. In a classroom battle, Kurage-bo helps Masashi by defeating Yupi with impressive kung-fu.

Naoto, Masashi's uncle who works at the local research center, visits and cautions that the town may be dangerous. He asks Masashi to report anything unusual and takes note of Kurage-bo in Masashi's backpack. The family atmosphere grows tenser as mystery deepens.

Masashi and his classmates stage fights with their F.R.I.E.N.D.s on shrine grounds, sparking a larger battle. Luxor appears alongside Kurage-bo, revealing that Kurage-bo is Saki's F.R.I.E.N.D. Saki explains that top researchers gave all children devices to create loyal companions.

During a university festival, Shizuko's protest against the research center escalates tensions. Masashi and Saki slip into the research center, where the Black-Cloaked Four discuss plans to trap Masashi and seize control of the situation.

Tatsuya and Juran, learning Naoto works at the center, kidnap Kurage-bo. The abduction shakes Masashi and Saki and reveals the lengths the conspirators will go to capture powerful energy.

While visiting Masashi, he is knocked unconscious by Yupi and ends up hospitalized. Naoto provides Masashi with a Device to protect him, though something about it feels off and coercive.

Masashi is told that Naoto died after falling from a building. In the forest, Kurage-bo is missing and later found beaten and locked in a junkyard locker, signaling the enemies' reach and cruelty.

Back in the lab, Koh faces Yupi and Shimon alongside Ko2. Masashi is saved from imminent danger as the pair confront the clone Naoto. The real Naoto appears and a confrontation follows to reveal the true intentions behind the deception.

The Cloak Four reveal their plan to trap Masashi for negative energy, confirming the Oval threat. They realize they must rally all F.R.I.E.N.D.s to confront the looming disaster, and Koh begins to locate the Oval's weak spot.

The town mobilizes as all F.R.I.E.N.D.s are summoned to fight the Oval. Saki tries to rescue her mother from the Oval's ferocity and nearly falls, but Masashi saves her. Masashi identifies the Oval's weak spot and destroys it, causing the F.R.I.E.N.D.s to spiral into a vortex, with Kurage-bo among those affected.

Koh uses his device to restore all F.R.I.E.N.D.s to the real world. Masashi, Saki, Kurage-bo and their friends reunite, embracing a hopeful future and choosing to continue their bonds of friendship together.