So I went and actually did some research this time, and it seems I was wrong before. This problem does apply to a lot of the anime that specifically I am interested in, but there are a lot of titles that don’t present with this issue. Looking at the all the anime I could find on Netflix that I had previously heard of, I split them into four categories:
(I’m sure I missed quite a few, but it should be enough to make my point.)
A: Both Japanese and English available in same location (no VPN required)
- BAKI
- BEASTARS
- The Irregular at Magic High School
- The Way of the Househusband
- Kakegurui
- Violet Evergarden
- High-Rise Invasion
- A Whisker Away
- Howl’s Moving Castle
- BNA
- Kiki’s Delivery Service
- JoJo’s Bizarre Adventure
- My Neighbor Totoro
- Ponyo
- Angel Beats
- Tokyo Ghoul
- Fullmetal Alchemist
- Teasing Master Takagi-san
- Spirited Away
- The Disastrous Life of Saiki K
- Dorohedoro
- The Great Pretender
- Little Witch Academia
- Flavors of Youth
B: Both Japanese and English available in same location (requires VPN)
- Toradora (India/Japan)
- A Silent Voice (Japan)
- Sword Art Online (Japan)
- Steins;Gate (Japan)
- The Garden of Words (India/Malaysia/Philippines/Singapore)
C: Japanese and English not available in same location
- Haikyuu
- Seven Deadly Sins
- Demon Slayer: Kimetsu no Yaiba
- Food Wars!: Shokugeki no Soma
- Attack on Titan
- Monthly Girls’ Nozaki Kun
- Erased
- Your Lie in April
- Anohana: The Flower We Saw That Day
- Asterisk War
- One Piece
- No Game No Life
- Pop Team Epic
- March Comes In like a Lion
D: Japanese subtitles unavailable (in any location)
- Naruto
- Naruto Shippuden
- Re: Starting life in another world from zero
- Parasyte: The Maxim
- Death Note
- Blue Exorcist
- Your Name
- Love, Chunibyo and Other Delusions
- One Punch Man
- Black Butler
- Akame ga Kill!
(I got my information from uNoGS.com, but made sure to test a fair few of them to be sure it was right. For reference, I live in the UK.)
So there is actually a large amount of anime that can be viewed with English and Japanese subs without extra tools like VPNs (categorty A), which is great! Thanks for prompting me to investigate.
With a VPN, there are a handful more titles that can be viewed with dual subtitles (category B).
However, there are a fair number of (fairly popular) titles that cannot be viewed with dual subs, either because of the issue I mentioned previously (category C) or because Japanese subs are unavailable at all (category D). I think it is unfortunate to not be able to learn with these titles.
Being able to import subtitle files would solve the issue with titles in categories C and D. I checked and was able to find subtitles for all except one of the titles from C and D on kitsunekko.net.
Also, since scrubbing back to hear a line you missed while on a VPN can be really slow (at least for my VPN), I think having the option to add subtitle files would probably be much nicer than using a VPN in many cases (which would apply to titles in category B). Extensions for adding subtitle files exist out there (e.g. +Subs), but they don’t integrate well with LLN. In the past I have used +Sub with LLN for titles in category B (because while it leaves quite a lot to be desired, my VPN was being far too slow).