Yuusaku Horikawa, an unlucky guy who always got the girls that he was aiming for stolen by his childhood friend, Harumi. One day, they were in the elevator together and the blackout occurred. They're stuck in the elevator... What'll happen to them? (Source: Tamago Box)

Katakoi Troublemaker was originally published as two one-shots in drap Milk under the titles "Elevator Trouble" (エレベーターとらぶる) and "Renai Soudan Trouble" (恋愛相談とらぶる). The two stories were compiled into a booklet which was included with the special box set of the Katakoi Troublemaker drama CD in October 2016.