The Crawler In The Attic (2016)

Private investigator Kogoro (Kouta Kusano) is approached by Naoko (Yuki Mamiya), whose family operates a prominent hospital. Concerned about her fiancé Endo (Yasushi Fuchikami), Naoko suspects he may be unfaithful with Teruko (Noriko Kijima), a university student. Tasked with uncovering the truth, Kogoro delves into a web of secrets and lies, navigating the complexities of love and betrayal as he seeks to resolve Naoko's fears. The investigation leads to unexpected revelations, challenging Kogoro's own beliefs about trust and commitment in relationships.