Hello, Good-bye (ハローグッドバイ Harō Guddobai) is a Japanese adult visual novel developed and published by Lump of Sugar. It was released on December 17, 2010 for Windows as Lump of Sugar's sixth title. A trial edition was released in October 2010 rated for all ages. The primary focus of the game is the appeal of the four female main characters. The story resolves around the protagonist, Kaito Toubu, who is actually a secret agent with the ability to experience time loops.