Reiko Watanabe & Inspector Aizawa Books in Order

The Recommended Reading Order

Matthew Legare's Reiko Watanabe & Inspector Aizawa series blends the fast pacing of pulp fiction with meticulous historical research. The series is set against the backdrop of 1930s Tokyo, a chaotic period marked by political assassinations, rising militarism, and economic instability. While the main novels were published sequentially, Legare has also released prequel and companion novellas that fit into specific slots in the timeline.

For the best reading experience, you can choose between two primary paths: Chronological Order (which follows the historical timeline of the 1930s) or Publication Order (which introduces the characters as they were originally presented to readers). We highly recommend reading chronologically to fully appreciate the characters' growth and the evolving political landscape of interwar Japan.

Chronological Reading Order

Reading the series chronologically allows you to watch the steady degradation of Japan's democracy and the tightening grip of militarism in real-time. This order integrates the novellas directly into their respective spots in the timeline:

1. Conspiracy in Tokyo (Prequel Novella — set in March 1931)
2. Shadows of Tokyo (Book 1 — set in December 1931)
3. Smoke Over Tokyo (Book 2 — set in 1932)
4. Poison Across Tokyo (Inspector Aizawa Crime Novella #1 — set in September 1932)
5. Treason in Tokyo (Book 3 — set in 1933)
6. Secrets Beneath Tokyo (Book 4 — set in 1934)

Publication Order

If you prefer to read the books in the order they were written and released, follow this path. Note that the companion novella Poison Across Tokyo was released after Book 4, though it takes place earlier in the timeline:

1. Conspiracy in Tokyo (2018)
2. Shadows of Tokyo (2018)
3. Smoke Over Tokyo (2018)
4. Treason in Tokyo (2020)
5. Secrets Beneath Tokyo (2024)
6. Poison Across Tokyo (2025)

The Books in Detail

1. Conspiracy in Tokyo (2018)

Though published around the same time as the first novel, this prequel novella takes place in March 1931. The story focuses on Inspector Kenji Aizawa before his fateful partnership with Reiko. Working undercover, Aizawa attempts to infiltrate the "Kusanagi Society," a right-wing extremist group led by Masaru Ryusaki that is plotting a coup d'état against the civilian government. It is a fantastic introduction to Aizawa's sharp instincts and the political factionalism of the era.

2. Shadows of Tokyo (2018)

Set in December 1931, this is the official beginning of the main series. Inspector Aizawa receives a tip from Reiko Watanabe, a modern-minded geisha who also happens to be the mistress of Masaru Ryusaki. Together, they uncover a dangerous conspiracy to assassinate a major Japanese statesman. This book establishes their unique dynamic: Reiko acts as a high-society informant with access to powerful men, while Aizawa handles the gritty street-level police work.

3. Smoke Over Tokyo (2018)

Set in 1932, the second novel plunges Reiko deep undercover into the dangerous Yakuza underworld. Following the mysterious suicide of a high-profile politician, Aizawa and Reiko are drawn into a web of blackmail and corporate greed. The book highlights the tension between Japan's traditional values and the rapidly encroaching Western influences of the decade.

4. Poison Across Tokyo (2025)

This is the first entry in the Inspector Aizawa Crime Novellas, a companion series designed to explore shorter, self-contained cases. Chronologically set in September 1932, it finds Reiko keeping watch on a prominent businessman who has received a death threat. When the man is poisoned by a mysterious figure known as the "Poison Woman," Aizawa and Reiko must uncover a plot involving Korean nationalists and international espionage before a critical state banquet.

5. Treason in Tokyo (2020)

Set in 1933, the third novel deals with the assassination of an advisor to the Emperor. The investigation leads Aizawa and Reiko to target a radical communist gang. As political polarization reaches a boiling point, the protagonists find themselves caught between the extreme left and the rising fascist factions within the military.

6. Secrets Beneath Tokyo (2024)

Set during a scorching heatwave in the summer of 1934, the fourth novel sees Tokyo plagued by a series of devastating, suspicious fires. As Aizawa and Reiko hunt down a elusive serial arsonist, they expose corruption and secrets buried deep within the city's power structures, showing just how fragile the municipal government has become.

What to Know Before You Start

To get the most out of the Reiko Watanabe & Inspector Aizawa series, keep these practical elements in mind:

• The Historical Setting: The stories take place during the interwar Showa Era. Familiarity with events like the Manchurian Incident (1931) and the rise of the Showa Restoration movement will enhance your understanding of the political stakes, though Legare does an excellent job explaining these events within the text.
• The "Moga" Archetype: Reiko Watanabe represents the "modern girl" (moga) of 1930s Japan—independent, career-oriented, and influenced by Western fashion and ideas. Her contrast with traditional geisha expectations is a recurring theme.
• Pulp Noir Influence: Legare's style is heavily influenced by classic American pulp detective magazines and German Weimar-era noir, resulting in atmospheric, fast-paced mysteries rather than slow-burn police procedurals.