Two years ago, Katsuo Todo (Takashi Naito) was appointed as the general manager of the Plato Royal Hotel Yatsugatake from the Plato Tokyo hotel. He works hard every day with his staff to provide the best time and space for our customers. Concierge Shuji Kitayama (Hishine Saku Toshihide) struggles to find a benefactor for guests Pascal Henry (Frederick Benoliel) and his wife Shizuko (Ishino Yoko). The sweets made by young pastry chef Yoshiyuki Sudo (Shunsuke Tanaka) are popular with guests, and popular writer Fuyuki Nakagami (David Ito) even stays just to enjoy them. Sudo has also decided to marry Minori Matsuoka (Rio Yamashita), and Minami Yamashita (Michiko Amekumi), who is in charge of bridal services, is busy preparing for her colleague's wedding.

The strangled dead body of Hiroshi Hatano, accounting section chief at the longstanding apparel company Edaka International, is discovered in his apartment in Tokyo. At the scene, Inspector Totsugawa and Detective Kamei find out that a mysterious email stating "I'll be riding the Super Ozora 5 tomorrow" was sent to the victim's cell phone the night before. The sender, Manami Furuya, an employee of Edaka International's Planning Section, has strangely terminated her cell phone service and hasn't shown up to work that very morning. Immediately afterwards, Totsugawa is astonished to receive a report from the Hokkaido police stating that the body of a man, stabbed to death, has been found on the Super Ozora 5 limited express. The man is Yuuki Nakamura, a bar employee from Tokyo, who seems to have flown from Haneda Airport to Sapporo and then boarded the Super Ozora 5, which connects Sapporo and Kushiro. Totsugawa has the feeling that this can't be a coincidence...

Detective Kamei of the First Investigation Division receives a request from lawyer Shinichi Nakamura, the son of his deceased close friend, to re-investigate a car accident. Akiko, the wife of Yasuo Furuki, a painter from Hakone, died in the accident 5 months earlier by crashing into a guardrail. Nakamura's client, Akiko's younger sister Yuki Izeki, suspects that she was actually murdered by Furuki for insurance money. Overwhelmed by these thoughts, Yuki had sent an email reading "I'll never forgive that man. I'm going to kill him and avenge my big sister," announcing a murder to Nakamura. In the middle of their conversation, Nakamura receives a call from Hakone PD confirming that Yuki had turned herself in that morning...

Japanese rock band Ziggy comes to London and gets attacked upon arrival at the hotel after a recording session. The musicians barely escape the attack; however, soon they learn that their producer has been murdered, and they are the suspects! Chased by police and some mysterious organization, they find shelter at a local rockers' place and even give a performance there; but it is not too long before their pursuers appear again.

Inspector Totsugawa of the First Investigation Division goes to Tsuruoka in Yamagata to attend the wedding of the son of Inspector Mukai, his former colleague who now works for the Yamagata Prefectural Police. While sightseeing at Mt. Haguro after the ceremony, he notices a young woman drawing him in her sketchbook. She introduces herself as Yuka Shiraishi and says she came to draw the Dewa Sanzan. Signing the drawing of Totsugawa next to the five-story pagoda with her initial, a 'Y' in the corner, she gives it to him as a present. The next morning, the corpse of a young woman who has been stabbed is discovered in a forest in Tsuruoka. When Totsugawa, on his way back, hears that a sketchbook signed with a 'Y' was found at the scene, he follows Mukai there. However, the body is not Yuka, the woman Totsugawa had met, and while no items pointing to her identity are found, the sketchbook is the same one Yuka had the day before.