Stop!! Hibari-kun! - Season 1 Episode 25 Love Under the Palm Trees!!
Overview: Kōsaku and the Ōzora's end up stranded on a desert island. Ibari has a heart attack when he realises the natives can speak Japanese. They are joined by Kawahana Hiroshi, who makes adventure television programmes. He mistakes them for cavemen, only to be thrown into the river by the real natives.