Yakusuke, suspected of being the one responsible for losing an SD card filled with confidential information at a research institute, engages the services of Kyoko Okitegami to vindicate himself.

A suspected killer, Kujirai, seeks a detective's assistance to validate his alibi. Kyoko was the one by his side during the murder, yet her memory of that fateful moment is blank.

While working as a museum security guard, Yakusuke witnesses an elderly man as he grows furious over a painting, damaging it. He seeks Kyoko's help to uncover the cause.

To create a picture frame for his culmination project, Wakui asks Kyoko and Yakusuke to safeguard the workshop. Upon arriving, they find Wakui has been stabbed, leading them to suspect one of his aspiring painters as the culprit.

Kyoko eagerly awaits a search event to uncover a new manuscript written and hidden by her favorite novelist, Sunaga. However, Yakusuke learns of Sunaga's death and is officially assigned to locate the manuscript.

In the midst of his duties as a janitor at a junior high school, Yakusuke stumbles upon a gas-filled room where he finds Masaka who has collapsed. Although they manage to survive, Yakusuke becomes the prime suspect in the crime.

A new possibility has emerged that Sunaga might have taken his own life. Hoping there could be concealed clues within his posthumous writings, Kyoko begins to read all 99 of his works without sleep to understand his state of mind.

One morning, Kyoko finds a note on her thigh, mentioning Yakusuke's reliability, a name she can't recall. Later, a customer's body is discovered in a store's fitting room, and Kyoko learns that Yakusuke is the first to find the body.

Kyoko's new task is decoding the safe's code, which was concealed within a message left by a missing vice president. In the meantime, Yakusuke has become wary of Sandglass and is launching an investigation into Houro.

Ten days after Kyoko disappeared from Sandglass, Yakusuke finds her with her hair that is now dyed black. She does not remember him and insists that Kyoko is not her name.