Koro Koro Danjo-Kun

Koro Koro Danjo-Kun is one of Lala's inventions.

In this name, Koro Koro means "easily changeable" and Danjo means "male and female" in Japanese.

This invention is a laser gun that discharges the beam shich temporally changes sex. But when the limit of the effect draws near, the eczema is gradually affecting and finally a fume rises when the effect completely wears off. It looks a laser gun with Deviluke's symbol at the side of this invention, black trigger and white, blue and magenta portions. But in Darkness, these portions are white, blue, red and yellow. A magenta portion is changed to yellow. This invention is only used for the appearances of Yusaku Riko in the series.

Appearance
Chapter 106: It is used by Lala for turning Rito into Riko for which she has a date with Saruyama. Rito has only an access to him because he is a friend aince childhood.

Chapter 131: It is used for pleasing Celine's desire, as it was from being expected to wound her and results in which Rito is.

Chapter 138: It is activated aaccidentarily when Lala falls it off from her hand because Rito goes down the staircase rapidly when he escapes from Yami and runs into with Lala. The beam hits Rito, and it is the third time that he is turned into a girl in the manga.

Chapter 8 of Darkness: It is used by Lala but this time it is intentional, she uses it for showing Mea the ability of changing sex of the memorzeans, for which it uses as an individual of the tests to Rito and shows Mea a similar transformation between Rito and Riko as between Ren and Run.

In the episode 3 of Motto To LOVE-Ru, it is used as well as in the chapter 106.

In the episode 5 of Darkness, as equal to the chapter 8 of Darkness, Rito is turned into Riko and after this action the invention doesn't discharge by which Riko follows appearance until the half of the following episode.

Trivia

 * It has a similar effect to Pai Pai Rocket-Kun, and the unique difference is that this experiment is more portable and has a temporal and short effect.
 * Besides Rito, no one has been affected by this invention.
 * It belongs to the inventions that change appearance at least once in the anime.