Sota Yukimura (Hokuto Matsumura) works in the secondary brand division of the cosmetics company "Nose Cosmetics." He goes on a Ferris wheel date with his boss, Mariko Nose (Sae Okazaki)—whom he has secretly loved for 25 years—and spends a dreamlike time with her... but that happiness is short-lived. His secret is exposed: he had attended the same junior high and high schools as Mariko all along. Upon realizing that Sota had been watching her from nearby for so long, Mariko is unable to hide her bewilderment and leaves him behind to go home... "It's over... my 25-year-long love..." Sota is devastated, believing Mariko now hates him... Meanwhile, the police—led by Detective Taisuke Sakura (Tetsuji Tamayama) of the First Investigation Division, who suspects Sota of murder—uncover the fact that Sota and Mariko attended the same schools and begin to speculate on a motive. They suspect that Sota, harboring an intense obsession with Mariko, may have killed Tsuyoshi Tateiwa (Tomomi Maruyama), a colleague who was vying with Mariko for a position within the company... Furthermore, Taisuke visits the detective agency Tateiwa had hired and obtains crucial documents that hold the key to the events leading up to Tateiwa's murder... Amidst this, Sota—determined to protect Mariko's happiness—grows suspicious regarding the accidental death of Mariko's biological mother, Kyoko, and goes to meet a certain individual... And finally, the true culprit behind Tateiwa's murder is revealed! Just who is the killer...!?

Sota Yukimura (Hokuto Matsumura) works in the secondary brand division of the cosmetics company "Nose Cosmetics." He has spent 25 years secretly acting from the shadows to protect the happiness of his boss, Mariko Nose (Sae Okazaki)—on whom he has a crush—but when his actions are exposed, Mariko tells him, "It's creepy!" Not wanting to scare her any further, Sota unfollows her on social media and begins to distance himself, avoiding even making eye contact with her at work. Meanwhile, despite what she said, Mariko finds she cannot get Sota out of her mind. Curious about his daily life, she takes her secretary, Izumi Takeda (Nozomi Sasaki), and her daughter, Sara (Seina Izutani), to tail Sota after work... Just as Sota is trying to cut ties with Mariko, his best friend, Tomoya Sagara (Akihisa Shiono), tells him, "I've got some huge scoop." Tomoya claims to have heard unsettling information that could threaten Mariko's happiness while attending the funeral of her stepmother, Sayuri (Miki Mizuno), who had been murdered. Normally, Sota would have sprung into action immediately to protect Mariko, but this time he refuses to get involved, saying, "That's not my job." He becomes self-deprecating, declaring, "I'm the kind of person who shouldn't even show his face in front of Mariko," and gives up on protecting her... Amidst this, the vengeful reach of Satoru Hatano (Yoji Tanaka)—a serial kidnapper who holds a grudge against Sota—is closing in fast! A terrible crisis is about to strike Sota and Mariko!!