# TBS drama LOST10 premiere and reception > Developing situation record from CLSTR: https://clstr.news/situations/tbs-drama-lost10-premiere-and-reception > Updated: 2026-10-31T01:21:22.000Z. Sources: 12. Developments: 5. The TBS suspense drama ‘LOST10’, set in Hokkaido, premiered with a plot centered on the ‘Shikaradake Incident’. The story follows a local detective, Ogoma (played by Ryusei Yokohama), and an insurance investigator, Nao (played by Shun Oguri), as they investigate a mountain climbing accident involving a tour guide and five participants. Early plot developments suggest the accident may involve criminal activity or insurance fraud, specifically noting that one survivor is the beneficiary of the other participants’ insurance policies. Following the premiere, viewer attention has focused on the cast performances. Yuki Saito has drawn notice for her portrayal of a suspicious character using distinctive makeup, while the appearance of King Gnu vocalist Rie Iguchi as a pediatrician has also been highlighted by audiences. The narrative reached a turning point in the second episode, transitioning from a survival story into a murder investigation. Following the discovery of a deceased participant, Nikaido, with sleeping pills in his system, investigations revealed that participant Aya Sawatari was the beneficiary of mountain insurance totaling up to 20 million yen. Conflicting testimonies have emerged between tour guide Motoka Tabata, played by Marie Iitoyo, and Sawatari, played by Anne Nakamura. The episode ended on a cliffhanger when Tabata jumped from an apartment rooftop in front of detective Komoma. In the third episode, police suspicion shifts toward Aya after fingerprints are found on a water bottle containing sleeping pills. Detective Komoma faces internal pressure from his superior, Endo, to extract a confession from Aya in exchange for a career promotion. Meanwhile, Nao discovers a 30 million yen life insurance policy, and new security footage from a Shibuya apartment shows a tour participant previously thought to be missing, potentially overturning established facts of the accident. ## Claims - The drama ‘LOST10’ is a TBS Friday night production. (reported by 3 sources) - Ryusei Yokohama stars in the lead role of Komoma. (reported by 3 sources) - Marie Iitoyo plays the character Motoka Tabata. (reported by 3 sources) - Motoka Tabata jumped from an apartment rooftop at the end of the second episode. (reported by 3 sources) - The plot involves a mountain accident called the ‘Shikaradake Incident’ in Hokkaido. (reported by 2 sources) - A tour participant named Nikaido was found dead with sleeping pills in his body. (reported by 2 sources) - Aya Sawatari was designated as the beneficiary for up to 20 million yen in mountain insurance. (reported by 2 sources) ## Timeline ### 2026-10-31: LOST10 drama episode 3 introduces new mysteries and character conflicts Episode 3 of the drama LOST10 escalates the investigation into the Shibaka-dake accident following a sudden death and new evidence from security footage. 2 sources. https://clstr.news/cluster/lost10-drama-episode-3-introduces-new-mysteries-and-character-conflicts ### 2026-10-27: TBS drama LOST10 explores mystery of Hokkaido mountain accident The TBS drama LOST10 follows a detective and an insurance investigator as they uncover potential foul play and insurance fraud following a mysterious mountain accident in Hokkaido. 3 sources. https://clstr.news/cluster/tbs-drama-lost10-explores-mystery-of-hokkaido-mountain-accident ### 2026-10-24: LOST10 drama features shocking plot twist in second episode The second episode of the TBS drama ‘LOST10’ concludes with a shocking scene where character Motoka Tabata jumps from a rooftop following conflicting testimonies in a mountain accident investigation. 4 sources. https://clstr.news/cluster/lost10-drama-features-shocking-plot-twist-in-second-episode ### 2026-10-18: LOST10 drama premiere draws attention to cast performances The TBS drama ‘LOST10’, starring Ryusei Yokohama, has sparked online discussion regarding Yuki Saito’s intense performance and the unexpected acting appearance of King Gnu vocalist Rie Iguchi. 2 sources. https://clstr.news/cluster/lost10-drama-premiere-draws-attention-to-cast-performances ### 2026-10-15: Ryusei Yokohama stars in new TBS suspense drama LOST10 The premiere of the TBS drama ‘LOST10’, starring Ryusei Yokohama and Shun Oguri, has sparked online intrigue following a suspenseful opening involving a suspicious mountain climbing accident in Hokkaido. 6 sources. https://clstr.news/cluster/ryusei-yokohama-stars-in-new-tbs-suspense-drama-lost10 --- Cite as: TBS drama LOST10 premiere and reception. CLSTR, https://clstr.news/situations/tbs-drama-lost10-premiere-and-reception