Before the one-star reviews do
Find plot holes before your readers do
You can't proofread your own logic. You wrote the story, so you read what you meant. Readers read what is on the page. Bunsho checks the page against everything your story has established, and shows its work.
The five plot holes readers actually catch
The contradiction
A fact established early is broken later: the sealed vault that opens without explanation, the dead character who walks in.
The timeline break
The festival happens two weeks before the chapter that sets it up. The journey takes three days once, and a week later.
The knowledge leak
A character acts on information they were never given. This is the most common hole in mysteries and thrillers, and the hardest to see yourself.
The broken rule
Your world has laws: magic costs, travel times, who can do what. A scene quietly breaks one, and the world stops being trustworthy.
The dropped thread
The injury that heals off-screen. The cane that vanishes mid-book. The promise made in chapter 4 that the ending forgot.
How Bunsho finds them
Bunsho reads your manuscript and compiles it into story state: a connected model of your characters, places, objects, timeline, and world rules, with every fact pinned to the sentence that established it. When you run a check, each scene is tested against that state.
A finding is never a vibe. It is a citation: the claim, the earlier passage it conflicts with, and both sentences side by side, so you can accept or dismiss it in seconds. If it can’t show you the receipts, it doesn’t flag it.
You decide when checking happens: one chapter before you move on, only the chapters that changed since your last review, or the full manuscript. Writing is never metered. The checker reads when you ask, not while you type.
What it deliberately won't do
Bunsho has no opinion on what should happen in your story, by design and enforced by regression test. It will not tell you the pacing is slow or the twist is weak; it is not a beta reader, and it is never the author. It checks your story’s facts against your story’s facts. The judgment calls stay yours.
If you want the deeper story of how fact-tracking works, see the continuity checker. If you want drafting that can’t create plot holes in the first place, that’s Director Mode.
Common questions
What is the difference between a plot hole and a continuity error?
A continuity error is a fact that drifts: an age, a location, an object. A plot hole is a break in the story's logic: an event that couldn't happen given what the story has established, a plan that only works because nobody mentions the obvious, a resolution that ignores an earlier rule. Bunsho catches both, because both are contradictions against the story's own state.
Can AI actually find plot holes?
It can find the checkable kind: contradictions against facts your manuscript establishes, such as who knows what, who is where, and what the world's rules are. That covers the plot holes readers leave one-star reviews about. What it deliberately doesn't do is judge taste: pacing, stakes, and whether your twist is satisfying remain your call.
Will it flag things that aren't really plot holes?
False alarms are the fastest way to make a writer stop trusting a tool, so the engine is benchmarked against decoys: passages designed to look like errors without being errors. The shipping gate requires zero of them flagged. Every finding cites the passages it believes are in conflict, so you can judge it in seconds.
Is my manuscript safe?
Your manuscript is local-first. It lives on your device, not in our database. When you run a check, only the pages being checked are sent for analysis, and they are never used to train models.
Your readers check continuity. Now you can too.
Bunsho is in private beta. Join the waitlist and put every chapter through a script supervisor before it ships.
Join the Waitlist