Season guide

The Decagon House Murders: Season 1

5 episodes Premiered Mar 22, 2024 Updated Sep 28, 2026

Season 1 Episodes

Episode Guide

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Season 1: Filler vs. Essential Canon

Filter episodes by narrative weight. Focus on essential mytharc and skip standalone side quests.

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Mytharc (3): Crucial lore & season climaxes

Core (2): Character development & subplots

Side Quest (0): Standalone / filler

S1·E1 Mytharc

Episode 1

Mar 22, 2024 · 53 min

Konan Takaaki, a former member of K University’s Mystery Research Club, receives a mysterious letter from Nakamura Seiji. Determined to uncover the truth, he visits Seiji’s younger

S1·E2 Mytharc

Episode 2

Mar 22, 2024 · 44 min

During a training camp at the Decagon House on Tsunoshima Island, a member of the Mystery Research Club is murdered. As suspicion spreads among the isolated group, Konan and Shimad

S1·E3 Core

Episode 3

Mar 22, 2024 · 48 min

Konan and Shimada continue their investigation but struggle to uncover any solid leads. While they question whether the mysterious letter might have been a prank, a terrifying inci

S1·E4 Core

Episode 4

Mar 22, 2024 · 46 min

Reviewing the clues they have gathered, Konan and Shimada develop a new hypothesis that could explain the tragedy at Aoyashiki. Determined to uncover the truth, they decide to trav

S1·E5 Mytharc

Episode 5

Mar 22, 2024 · 49 min

As the situation at the Decagon House grows more serious, Konan learns the shocking details of the incident from the police. Devastated by the deaths of his friends, he considers s