Season
- Season 1 2002-10-01
Episode
- Episode 1: Spiral of Destiny
- Episode 2: Seijyu: Hall of Death
- Episode 3: The Cursed Children
- Episode 4: The Fortune of Believers
- Episode 5: The Misty Gallows of Death
- Episode 6: The Blind Spot In The Net
- Episode 7: A Choice of a Nonbeliever
- Episode 8: Just a day of the Defeated
- Episode 9: All Things That Are Possible To You
- Episode 10: Only One Wise Action
- Episode 11: Good Night Sweetheart
- Episode 12: Dry Eyes
- Episode 13: Overture [prelude]
- Episode 14: Like A Sweet Aroma Haze
- Episode 15: Like A Swan
- Episode 16: The Uninvited Visitor
- Episode 17: The Watcher in the Darkness
- Episode 18: Angel of Sorrow
- Episode 19: Mirror of the Heart
- Episode 20: Whispering Shadow
- Episode 21: The Sound of Heartbreak
- Episode 22: The Mask's Confession
- Episode 23: Never Ending Rain
- Episode 24: The Man of the Lofty Castle
- Episode 25: The Sound of the Thawing Iris
Spiral: The Bonds of Reasoning Season 1 Only One Wise Action
Ayumu Narumi has lived all his life in the shadow of his famous detective brother, Kiyotaka. However, Kiyotaka disappeared two years ago, leaving behind his wife Madoka and Ayumu himself, along with a cryptic message about the "Blade Children."
One day, a girl at Ayumu's school suddenly dies. What seemed like a suicide at first glance turns out to be a murder, and Ayumu is the prime suspect. While investigating the person responsible for framing him, he discovers that the mysterious Blade Children are involved—and they somehow know Kiyotaka personally. Ayumu soon finds out just how dangerous the Blade Children are and learns that, in reality, he and Kiyotaka are intertwined more closely than he had ever believed.
