Series synopsis
The Case Book of Arne, also known as アルネの事件簿 is a Japanese animation mystery television series that premiered on Nippon TV on January 7, 2026. It ended on March 25, 2026. It stars Mariya Ise, Koki Uchiyama, Aimi Tanaka and Yuka Nukui.
Louis Hartmann loses his father, a private detective investigating a string of murders, leaving him all alone. Rumor has it that the murders are the work of a Grave-Digger Vampire. Louis isn’t keen on superstitions and vows to catch the culprit himself. That is, until a self-proclaimed detective, Arne Neuntöte, and his assistant, Lynn Reinweiß, appear. A new door is about to open for Louis…
Premise
Louis Hartmann loses his father, a private detective investigating a string of murders, leaving him all alone. Rumor has it that the murders are the work of a Grave-Digger Vampire. Louis isn’t keen on superstitions and vows to catch the culprit himself. That is, until a self-proclaimed detective, Arne Neuntöte, and his assistant, Lynn Reinweiß, appear. A new door is about to open for Louis…
Cast and characters
Leading cast
- Mariya Ise as Louis Hartmann (voice)
- Koki Uchiyama as Arne Neuntöte (voice)
- Aimi Tanaka as Young Arne Neuntöte (voice)
- Yuka Nukui as Lynn Reinweiß (voice)
- Yuki Sakakihara as Zisye (voice)
- Yuuki Shin as Nachzehrer (voice)
- Yoko Hikasa as Amy (voice)
Episodes
This series spans 1 season with 12 episodes.
| Season | Episodes | First aired | Last aired |
|---|---|---|---|
| Season 1 | 12 | January 7, 2026 | March 25, 2026 |
| Episode | Title | Air date |
|---|---|---|
| 1 |
Those Who Dig Pits for Others Will Fall In Themselves Louis Hartmann joins forces with the members of the Arne Detective Agency to investigate his father's murder. |
January 7, 2026 |
| 2 |
There Is Always Sunshine After the Rain Lynn remembers the time she first met Arne and hired him to help investigate her father's suspicious behavior. |
January 14, 2026 |
| 3 |
Misfortune Never Visits Alone Arne makes a shocking discovery about Lynn's father and Gordon reveals the dark truth of the Reinweiß mansion. |
January 21, 2026 |
Production
Release
| Original network/platform | Nippon TV |
|---|---|
| First aired | January 7, 2026 |
| Last aired | March 25, 2026 |
| Status | ended |
| Schedule | Tuesday at 01:30:00 |