A video was submitted to Big Summer's psychic investigator team. The video shows a couple visiting an abandoned well at a haunted place, the woman was attacked by a deformed monster that appeared from the well. The boyfriend now asks the team to investigate.

Love Shark is a wildly unhinged parody of Japanese paranormal TV and YouTube popularity culture. Natsume and Momoka run the failing psychic investigations channel Big Summer until a clickbait dating show they put on leads Momoka to find true love- with a contestant who is also a man-shark. Cue assassins, magic priests, decapitations, and chaos galore in this hysterical rom-com monster movie.

Psychic director Natsume and his assistant Momoka decide to infiltrate a yoga club after receiving a strange video. It showed a religious group that worshiped crocodiles called "Owa Jin", which Momoka's younger sister had joined a few years ago. What awaits the two who sneak in with the help of a shark?

In the treacherous frontier city of Samurai Town, a ruthless bank robber is sprung from jail by wealthy warlord The Governor, whose adopted granddaughter Bernice has gone missing. The Governor offers the prisoner his freedom in exchange for retrieving the runaway. Strapped into a leather suit that will self-destruct within five days, the bandit sets off on a journey to find the young woman—and his own path to redemption.

Team members Nishikawa, Momoka and Natstume, of “Psychic Investigations Big Summer” (PIBS), investigate supernatural phenomena and tales of the occult. They receive a video filmed at a haunted location, which shows a pair of media influencers filming a deserted, ancient stone well, and a shark-like monster that emerges and attacks the woman! PIBS begins an investigation of the tape, seeking info on the creature while they assist they search for the now missing influences. However, they find the local villagers won’t reveal the mysterious well’s location. PIBS digs deeper, but as they uncover clues and get closer to the cursed spot, they too are attacked by the shark. They escape, but things take a twist when Natsume becomes possessed by a supernatural spirit.

A lonely 40-year-old man falls for the woman he believes is fate. Guided by his late mother’s shark figurine and visions of a giant shark, he’s pulled into love, loss, and a strange awakening.