How a Developer Built the Best Tachiyomi and J2K Hybrid in the Yokai Reader

When the original Tachiyomi project shut down in early 2024, it created significant chaos among manga and comics enthusiasts on Android. The popular open-source reader fragmented into dozens of forks. Users were faced with a choice: Mihon continued the base application lineage, TachiyomiJ2K remained a favorite thanks to its thoughtful interface, and TachiyomiSY developed specific library filters.

Developer null2264 took a different approach. Rather than choosing between branches or tolerating the shortcomings of each, they decided to combine the best features from different authors into their own project called Yokai.

What Yokai Is

Yokai is a free, open-source Android reader written in Kotlin. The author states upfront in the repository that the project was created for personal use. In their profile, it's part of a so-called "paranormal" collection of forks — experiments where they explore new technologies, try refactoring, and add features that would unlikely be accepted into the main repository via Pull Request.

The app combines three major development branches:

1. Core and stability from Tachiyomi and its direct successor Mihon.
2. Interface solutions and UX from TachiyomiJ2K.
3. Content filters from TachiyomiSY.

The result feels cohesive: you get familiar reading functionality with convenient gesture controls and flexible layouts that previously required searching across different builds.

Key Features and Conveniences

Instead of blindly copying code, the author did serious work on targeted feature integration. Here's what stands out in practical use.

Advanced Interface from J2K

The main difference between Yokai and standard Mihon is how it handles the screen and library grid. The app actively uses Material Design You elements:

• The manga card screen adapts the interface color scheme to match the cover.
• A floating search bar helps quickly filter titles while scrolling.
• For tablets and foldable phones, there's a two-page spread mode like in a printed book.
• The bottom toolbar is expanded for comfortable one-handed control on large screens.
• Categories in the library can be collapsed into a single vertical list or dragged for manual sorting.

Local Reading and ComicInfo.xml File

Many users employ these readers not only for online catalogs but also for reading local CBZ and ZIP archives. In base Tachiyomi, files in folders often display with custom or broken chapter names.

Yokai added parsing of the ComicInfo.xml file inside local archives. The app automatically pulls the exact chapter number, original title, and translator information from metadata.

Library Organization and Backups

The author fixed a long-standing issue with backup incompatibility between different forks. Now a backup from Yokai deploys cleanly in other current clients.

For library structuring, the NSFW/SFW toggle system was ported from TachiyomiSY. Additionally, dynamic categories work automatically: the app groups titles by tags, tracking status, or source.

Tracker Synchronization

Like the original reader, integration with popular tracking services remains:

• Shikimori
• AniList
• MyAnimeList
• Kitsu
• MangaUpdates
• Bangumi

When a chapter is read, the progress is automatically sent to the selected platform.

Technical Side and Development Status

From a code perspective, Yokai is a classic Kotlin Android app requiring Android 6.0 or newer. The repository has CI/CD configured via GitHub Actions, which builds both stable versions and nightly builds on each commit.

In the repository description, the author notes that the focus has shifted to migrating the project to more modern infrastructure. Part of the codebase is being rewritten for current Jetpack libraries and updated Android 12+ guidelines.

Update schedule is irregular: periods of high activity are followed by pauses. This is an honest pet project of one person, not a corporate product with strict deadlines. However, the Apache-2.0 open license allows anyone to clone the repository and submit their own Pull Request.

Who This Project Is For

The app will be useful for several categories of users and developers:

• Owners of tablets and large-screen devices who miss the two-page mode in standard Mihon.
• Those who prefer to store comics locally and catalog them via ComicInfo.xml.
• Android developers interested in seeing an example of deep refactoring and merging codebases of major open-source Kotlin projects.

Summary

Yokai demonstrates a good example of how a personal fork for one's own needs can grow into a convenient tool for the community. The project doesn't try to reinvent the wheel; it takes the best from the scattered branches of the Tachiyomi ecosystem and packages it into a tidy interface.

If you've been looking for a reader with flexible library customization and tablet support, consider downloading the APK from the Releases section on GitHub and trying it out.