About Suikou AI

Why this tool exists

The name Suikou (推敲) comes from a classical story about a poet who agonized over a single verb — whether to write “push” or “knock” on a gate. In Japanese it has come to mean the patient work of polishing a sentence until it is exactly right. That is the entire premise of this product: AI can produce a draft in seconds, but turning that draft into prose that actually sounds like a person still takes deliberate revision. Suikou AI automates that revision pass without flattening your meaning.

The project started as a side experiment. While finishing a master’s in Intelligent Information Science at Kyoto University — focused on Japanese morphological analysis — I kept noticing that the humanizer tools on the market were built almost entirely for English student essays. Run Japanese through them and the output was subtly broken: verb conjugations drifted, particles like は/が and を/に were swapped in ways no native writer would produce, and the kanji-to-kana ratio swung unnaturally. The tools had no model of how Japanese actually holds together at the morpheme level, so they could not “naturalize” it — they just paraphrased it into something stranger.

After three years as an NLP engineer at a Tokyo SaaS company, I built a small scorer that rated how “natural” a piece of AI-generated Japanese felt, using explicit morphological features. The scorer turned out to be more useful than any single rewrite: if you generate several candidates and let a detector pick the most natural one, you get reliably better results than trusting a single pass. That scorer-plus-generator loop is the core of Suikou AI today.

How it works

For each request we generate three independent rewrites with DeepSeek at temperatures 0.6, 0.8, and 1.0, then score every candidate with a separate Qwen-72B detector and return the version with the lowest AI signature. For Japanese, the rewrite prompts carry extra constraints on conjugation form, particle usage, and kanji ratio — the morphological knowledge that general-purpose tools skip. The same architecture extends to English, Korean, German, and Traditional Chinese, which is why Suikou AI is a global tool with a Japanese specialty rather than a Japan-only one. The detector is also available on its own, free and unlimited, because checking whether text reads as AI-written is genuinely useful even when you are not rewriting it.

Suikou AI is built for legitimate refinement — polishing your own drafts, smoothing translations, and helping non-native writers sound natural in academic and professional work. It is not built for passing AI-generated work off as original under a no-AI policy, and our Terms of Service prohibit that use. Your text is never used to train models and is deleted on a fixed schedule tied to your plan.

Who runs it

Suikou AI is an independent project run by a Kyoto-based indie developer (Ryota Nishiyama). The business is operated through an entity registered in Hong Kong SAR, with payments processed via Stripe. There is no large company behind it — just one developer who cares about the difference between text that is technically correct and text that actually sounds human. Questions, feedback, and press inquiries are welcome at [email protected].