The Kichigai Record (or lunatic record) is a vinyl record appearing in Episode 16, "A Murderer Record’s Melody of Terror". It is a vinyl created by Jurals so that anyone that listens to the dreaded melody will lose their mind and become deranged. It's effects are seen on a few customer's at a music store early in the episode. The Jurals, realizing Ken's sister is one of the customers, ends up swapping out a "Johnny" vinyl with the Kichigai Record. When Caron brings it home to play for everyone, they all begin to cry in agony. The music is so awful it hurts their ears. Only Barican can save them due to him being a robot and not affected by the tune. He ends up smashing the record where it bursts into flames.
Ken takes his sister back to the store to confront the employees (jurals) and exclaims "How dare you sell such a lunacy record!!" (よくもあんなキチガイレコードを!; Yokumo anna kichigai record wo!). This line is one of the most famous lines spouted by Ken. It is most heavily used in MADs and the word "Kichigai" has now become associated with the series.
A chase ensues and Ken ends up defeating the Jurals so that no more evil records can be sold.
Note; The actual melody of the Kichigai Record is one of the background tracks already in the show, and it appears almost every single episode. the tune itself is quite annoying and has become famous itself.