Japanese Reading Assistant: Keeping lookup, grammar, and PDF OCR in the reading flow

The most disruptive part of Japanese reading is often not one unknown word. It is moving back and forth between a dictionary, translation, grammar notes, and the original line. This plugin keeps those actions on the current Obsidian page: a short selection opens a compact lookup, while a sentence is sent to the model once and becomes linked vocabulary and grammar views.

The repository is public: Normanchine/obsidian-japanese-reading-assistant. It can currently be installed manually from GitHub Releases or through BRAT as a beta plugin; it is not yet listed in the Obsidian Community Plugins directory.

One analysis, anchored to one sentence

The aim is not a long generic explanation. A sentence retains one shared translation; the vocabulary view separates dictionary meaning from the meaning in this sentence, and the grammar view connects colored, wavy source fragments to short notes. That keeps an explanation from becoming detached from the text it is meant to explain.

The vocabulary view starts from the current sentence. “In sentence” describes the word’s role here rather than creating a new dictionary entry.

The grammar view marks 「〜です」 in the sentence and explains its judgment or explanatory role here. Results appear in a non-modal window that can be pinned, moved, and resized without replacing the source text.

PDF text without leaving Obsidian

Textbooks and scanned readers do not always provide selectable text. In Obsidian’s built-in PDF viewer, holding Alt and drawing a small region sends that region to a local PP-OCRv5 service. The recognized text then follows the same translation, vocabulary, and grammar path as a normal sentence.

OCR receives only the region the reader draws, rather than the entire PDF. Results depend on the source image and page scale; zooming in is safer for small print.

The feature deliberately stays local and narrow. It does not turn a PDF into a complete ebook, and it does not create a persistent note from every OCR result. It is intended for understanding the line currently being read.

Models, data, and installation boundaries

Text analysis can use local Ollama or a user-configured DeepSeek-compatible endpoint. Their boundaries differ: Ollama may run on the device or at a trusted LAN address; the DeepSeek mode sends the current selection and a fixed analysis prompt to the configured API. The plugin does not upload whole notes, filenames, Vault paths, or nearby notes, and has no telemetry. The PDF OCR service listens on local 127.0.0.1, and selected images are not written to the Vault.

Installation requires Obsidian 1.11.5 or later and one configured text-analysis provider. PDF OCR also requires a local PP-OCRv5 service. The repository README documents manual installation, BRAT, and the OCR environment.

What remains unproven

Results currently live only in memory. Vocabulary cards and spaced-repetition export are not persistent features yet. PDF OCR targets the visible page of Obsidian’s built-in PDF view; it is not a general recognizer for EPUB, Canvas, or third-party readers. Output quality also depends on whether the chosen model reliably follows the structured JSON format.

The plugin is therefore a focused assistant for the moment of reading, not a complete Japanese course or memorization system. A useful next test is whether review cards truly reduce the post-reading organization cost before adding them.