Japanese Input is hard to setup

[ftphikari]

Problem

Just try doing it. First of all, there are 2 panels, layouts and inputs methods, already confusing. If I set a single layout (English) and several input methods (English, Ukrainian, Japanese), Ukrainian doesn't work, since it needs its own layout. If I instead set 3 layouts (English, Ukrainian, Japanese), and 1 input method - then Japanese doesn't work properly, input method doesn't get attached to the layout, so when I switch layouts with Alt+Shift, there now appear 2 different Japanese in the widget - jp and ja. Jp from layout, and ja from input method. So I'm thinking, okay, I need to have 2 layouts (English, Ukrainian), and 1 input method (Japanese Mozc). Now when I do Alt+Shift, it switches between 3 languages properly, except Japanese doesn't work at all now, since it for some reason uses last layout as its own layout, which happens to be Ukrainian in this case. So the actual solution is to setup layouts that I need, set English as the last layout, and then add Japanese input method. This way when it switches to Japanese input method, it always uses last layout, which is English, and works properly. This is extremely confusing and limiting, since now I can't have English as my first input method, which is what i use most of the time.
Also, this is a Mozc issue I think, but by default it uses Direct Input, so it's equivalent to English basically. It does the same thing in Windows, but you can change it to Hiragana with Alt+tilde. But here you cannot, I was only able to change it to Hiragana by actually pressing the pop-up on the screen under the cursor. See this screenshot:

This issue has been plaguing Windows since the 90s, the fact that you can't even start typing in Japanese when you switch to Japanese.

Proposal

Just make it the same as MacOS - a single layout panel, on which you choose the language/input method. You then switch between them. And when you choose Japanese - you can start typing in Japanese immediately. That's it.

Prior Art (Optional)

MacOS is the only OS for PCs that actually does this right. I would like to see Elementary fix this issue as well.

[jeremypw]

A related irritation is that the "switch layout" shortcut in fact cycles through both keyboard layouts and input methods while the "switch engine" shortcut only cycles through input methods. In it is not clear what the purpose of having both shortcuts is tbh (I have now proposed a PR that allows disabling the latter (see #498). Does it help to go into Ibus Preferences (type "ibus" in the Applications Menu) and choose "Use System Keyboard Layout" in the "Advanced" tab?

[jeremypw]

Setting both and English layout and an English input method is not necessary. Just install a layout that corresponds to the actual physical keyboard you have. Then install an input method for any language that cannot be typed directly using that layout. That's what I do to type Japanese anyway.