The Testimonial of Kyouko Okitegami

The first instalment of the Boukyaku Tantei Series. 

Okitegami Kyouko, also known as the forgetful detective. She forgets everything in a day, and solves cases (almost) immediately! An unfortunate young man, Kakushidate Yakusuke, gets caught up in every case and is always the prime suspect! He cries out, "Please let me call a detective—!!!" 

A swift development, a fleeting memory.
Will Kyouko-san be able to solve the case before she forgets its details? 

(Source: Kodansha, translated)

The third instalment of the Boukyaku Tantei Series. 

Kujirai, a man not aiming to commit a perfect crime. The beautiful woman he chooses as his "alibi testimony" is a white-haired detective who, worst of all, can only remember one whole day...... In the latest short story, "Okitegami Kyouko's Alibi Testimony," where the forgetful detective becomes a witness in a murder case. The newest story in the Forgetful Detective series brilliantly written by NISIOISIN! 

(Source: Kodansha, translated)

Twenty-five-year-old Kakushidate Yakusuke suffers from the fate of constantly stumbling into various crime scenes and ending up being the main suspect.

His last resort: Okitegami Kyouko the "Quickest Detective." However, Kyouko suffers from a strange case of amnesia; whenever she falls asleep, she forgets everything that happened the previous day, making her solve the mysteries within one day. 

*Note: Includes 4 extra chapters.*