Miru

Miru plays the videos on your own Jellyfin server through mpv, so it handles the files anime fansubs and Blu-ray rips come in. Japanese subtitles are drawn by Miru itself: tap any word for the dictionary popup, and mine it to Anki with a picture and the line’s audio. Every line you watch is kept in Lines, where you can read and search it later.

What you need

A Jellyfin server and a user account on it.
Japanese subtitles: text subtitles in your Jellyfin library (SRT, ASS and the like, separate or inside the video), or a free Jimaku account to find them, or Kaku to make them from the audio.
Optional, for mining: Anki with AnkiConnect. See Lookup and Anki.

Connecting Jellyfin

The first time you open Miru, setup asks for your server address (for example https://jellyfin.example.com), your username and your password. The password is only used to sign in: Miru keeps a sign-in token, never the password. Then it shows your Jellyfin libraries and asks which ones are Japanese. Getting started covers the rest of setup.

Later you’ll find the server in Settings → Jellyfin (with Sign Out and Test Connection), and the libraries in Settings → Libraries.

Browsing

Miru has four tabs: Watch, Lines, Stats and Settings.

Watch opens with Continue Watching, Next Up, what’s On This Device, and each library’s recently added titles. Search finds shows and movies by name.
A show’s page lists its episodes, with a filter: All, Unwatched or Downloaded.
Japanese audio only: in Settings → Playback, turn this on for a library to hide movies and shows without a Japanese audio track. Episodes with several audio tracks always start on the Japanese one.
On iPad and Mac, your libraries are also listed in the sidebar under the tabs.

Watching

Playback picks up where you left off, here or on any other Jellyfin app.

On iPhone and iPad:

Tap to show the controls, or tap with two fingers to pause without them.
Double-tap the left or right side to skip back or forward.
Drag sideways to scrub, with a preview of the picture.
Drag up or down along an edge to change the brightness or volume.

On the Mac, click to show the controls and double-click for full screen. The video plays in the main window; Escape closes it.

When an episode ends, an Up Next card counts down to the next one (pause to hold it, or cancel it). After a movie or a show’s last episode, Miru suggests something similar under You might like.

The screen stays on while a video plays, and the sound keeps going when you leave the app.

Tapping subtitles

Japanese subtitles show as text you can tap. Tapping a word pauses the video and opens the dictionary popup; closing it plays again. The popup’s Add to Anki makes a card with:

the subtitle line as the sentence,
the line’s audio, cut from the video,
a picture: a Screenshot or an Animated GIF of the line, chosen under Card Picture in Settings → Anki,
the show and episode, and the time.

Words you haven’t mined yet, and words you’re still learning, are underlined (see word marks). If the episode has English subtitles too, they can show at the top of the picture (the E key on a keyboard).

Skipping intros

When Jellyfin knows where an episode’s intro, recap, credits or preview is (for example from an intro-detection plugin on your server), a Skip Intro (or Skip Recap, Skip Credits…) button appears at that moment. To skip intros and recaps without the button, turn on Skip Intros Automatically in Settings → Playback.

Now Playing and AirPods

Miru shows on the Lock Screen and in Control Center, where you can pause and scrub. With AirPods:

Press to play or pause.
Double-press to go to the next line.
Triple-press to go back to the line before the one on screen, to hear it again.

The media keys on a Mac keyboard work too.

Subtitles

The subtitles button in the player opens the Subtitles sheet: the Japanese tracks Jellyfin has, the file you picked, and the timing.

Jimaku

Jimaku has Japanese subtitles for most anime. Make a free account there, create an API key on its Account page, and enter it in Settings → Subtitles → Jimaku. Then Find on Jimaku… in the Subtitles sheet searches for the show and lists its files. (When an episode has no Japanese subtitles at all, the player shows a Find Subtitles button that does the same.) The file you pick is kept on your device for that episode and wins over Jellyfin’s own tracks.

Nothing goes to your Jellyfin server unless you ask: Save to Jellyfin… in the Subtitles sheet (after a confirmation) adds the file, with your timing, next to the episode on your server.

Transcribing with Kaku

For an episode nobody has subtitled, Kaku can make Japanese subtitles from the audio. Set up Kaku in Settings → Subtitles → Kaku, then in the Subtitles sheet choose Transcribe with Kaku, or Transcribe the Rest of the Season for the later episodes too. The sheet shows Kaku’s progress or your place in its queue.

The result is labelled “From Kaku” and works like a Jimaku file: you can tap it, sync it, save it to Jellyfin, and watch with it offline. When you open an episode that has no Japanese subtitles, Miru checks Kaku and uses a finished transcript by itself.

Fixing the timing

Subtitles from elsewhere are often a little early or late. In the Subtitles sheet’s Timing section:

Nudge them by 1 second or 0.1 second at a time, or Reset.
Auto-Sync to the Audio lines the whole file up for you: against the video’s own subtitle tracks if it has any, or else by listening to the speech in the audio.

Retiming keeps a copy on your device; Jellyfin gets it only when you save.

Lines

Lines is a history of what you’ve watched, with the Japanese subtitles of each episode. It includes episodes watched in any Jellyfin app on any device, not just Miru.

Open an episode to read its lines. Tap a word to look it up, or use Play from Here to jump into the video at that line.
Search finds a word or phrase across every saved episode; inside an episode, search just that one.
Watching Now shows what another device is playing from your libraries, with its subtitles following along live. Tap words as they go by, scroll back, and Follow to catch up. You can also pause and resume that device from here.

Keyboard shortcuts

With a keyboard on the Mac or iPad, most of mpv’s familiar keys work: Space to pause, ← and → to seek, ↑ and ↓ for the previous and next line, [ and ] for speed, Z and X to move the subtitles, S to skip an intro, A to look up the current line, and more. Press ? over the video, or open Settings → Keyboard Shortcuts, for the full list.

Downloads

On a show’s page, download single episodes or several at once. Each is the original file, often 1–2 GB, together with its subtitles. Downloads wait for Wi-Fi unless Download over Cellular is on in Settings → Downloads. Nothing downloads unless you ask.

Downloaded episodes play offline, with lookups and mining. Manage them in Settings → Storage, which also holds the saved subtitles Lines uses.

Progress sync

While you watch, Miru reports to Jellyfin as any Jellyfin app does: your place, pauses and the episode you’re on, so Jellyfin’s resume points and “watched” marks stay right. If you watched further on another device meanwhile, Miru moves there when you come back. Reports made offline are sent later.

Stats

The Stats tab shows your watching time by week, month or all time, with lookups, cards mined and your streak. Only time that actually played counts, not seeking. Your kechimochi log can show there too (Settings → Stats).

Settings

Watching: Jellyfin, Libraries, Subtitles (Jimaku and Kaku), Playback (skip intros, Japanese audio only), Downloads, and Keyboard Shortcuts on iPad and Mac.
Lookup and Mining: dictionaries, word audio sources and Anki, including the card picture. See Lookup and Anki.
Stats: the kechimochi address.
Storage, Advanced (sharing the setup with your other apps, things waiting to sync, Run Setup Again, Export Logs) and About.