This TV-show name is "Tensai Takeshi no Genki ga deru Terebi" (TV taking heart with Genius Takeshi, known as Genki TV). TV host is Takeshi Kitano.
This clip is called 'Troop of One Hundred', where a 100 people chase after random strangers and you see their reactions. Totally harmless but their reactions are priceless.
- For the 1st and 2nd guys, they shout: "Here come the tsunami!!" (tsunami da!)
- For the 3rd guy they shout: "it's that guy!!" (aitsu da!)
- Nothing for the 4th guy
- Last scene: "Heads up! (danger)" (abunai!)