Ubuntu – How to install the Japanese keyboard layout in Lubuntu 18.10

What must I do to type in Japanese?

I wish to use fcitx-mozc as Wakisaka recommends, but when I add 'Keyboard – Japanese' via Preferences > Fcitx Configuration, I get only a qwerty layout with Roman letter output, no Japanese formed by typing a Japanese word like 'sore'.

When I uncheck 'Only Show Current Language' and search 'Moz', there is no Mozc option.

In 'Keyboard and Mouse' via Start search > Keyboard Layout, I have "Keyboard model: Dell Latitude laptop" because this laptop is a Dell Latitude D620. I have tried adding the Keyboard layout: Japanese there, too, with Super+Space to switch, but still no Japanese output. The 'kana' variant does let me type katakana from each key, but I need to be typing in qwerty or dvorak converting hiragana to kanji or katakana.

I wonder if I have found a hint: An 18.04 user was told to edit /usr/share/ibus/component/mozc.xml, but my folder lacks this file.

Edit: I have now installed fcitx-mozc.

$ sudo apt install fcitx-mozc
[sudo] password for username: 
Reading package lists... Done
Building dependency tree       
Reading state information... Done
The following additional packages will be installed:
  libprotobuf10 libzinnia0v5 mozc-data mozc-server mozc-utils-gui tegaki-zinnia-japanese
Suggested packages:
  ibus-qt5
The following NEW packages will be installed:
  fcitx-mozc libprotobuf10 libzinnia0v5 mozc-data mozc-server mozc-utils-gui tegaki-zinnia-japanese
0 upgraded, 7 newly installed, 0 to remove and 1 not upgraded.
Need to get 30.9 MB of archives.
After this operation, 53.5 MB of additional disk space will be used.
Do you want to continue? [Y/n] y
Get:1 http://us.archive.ubuntu.com/ubuntu cosmic/main i386 libprotobuf10 i386 3.0.0-9.1ubuntu3 [738 kB]
Get:2 http://us.archive.ubuntu.com/ubuntu cosmic/main i386 mozc-server i386 2.23.2815.102+dfsg-2 [11.9 MB]
Get:3 http://us.archive.ubuntu.com/ubuntu cosmic/main i386 mozc-data all 2.23.2815.102+dfsg-2 [11.1 kB]                                                    
Get:4 http://us.archive.ubuntu.com/ubuntu cosmic/main i386 tegaki-zinnia-japanese all 0.3-1 [17.3 MB]                                                      
Get:5 http://us.archive.ubuntu.com/ubuntu cosmic/universe i386 fcitx-mozc i386 2.23.2815.102+dfsg-2 [258 kB]                                               
Get:6 http://us.archive.ubuntu.com/ubuntu cosmic/main i386 libzinnia0v5 i386 0.06-3ubuntu1 [63.3 kB]                                                       
Get:7 http://us.archive.ubuntu.com/ubuntu cosmic/main i386 mozc-utils-gui i386 2.23.2815.102+dfsg-2 [737 kB]                                               
Fetched 30.9 MB in 14s (2,178 kB/s)                                                                                                                        
Selecting previously unselected package libprotobuf10:i386.
(Reading database ... 242486 files and directories currently installed.)
Preparing to unpack .../0-libprotobuf10_3.0.0-9.1ubuntu3_i386.deb ...
Unpacking libprotobuf10:i386 (3.0.0-9.1ubuntu3) ...
Selecting previously unselected package mozc-server.
Preparing to unpack .../1-mozc-server_2.23.2815.102+dfsg-2_i386.deb ...
Unpacking mozc-server (2.23.2815.102+dfsg-2) ...
Selecting previously unselected package mozc-data.
Preparing to unpack .../2-mozc-data_2.23.2815.102+dfsg-2_all.deb ...
Unpacking mozc-data (2.23.2815.102+dfsg-2) ...
Selecting previously unselected package tegaki-zinnia-japanese.
Preparing to unpack .../3-tegaki-zinnia-japanese_0.3-1_all.deb ...
Unpacking tegaki-zinnia-japanese (0.3-1) ...
Selecting previously unselected package fcitx-mozc:i386.
Preparing to unpack .../4-fcitx-mozc_2.23.2815.102+dfsg-2_i386.deb ...
Unpacking fcitx-mozc:i386 (2.23.2815.102+dfsg-2) ...
Selecting previously unselected package libzinnia0v5.
Preparing to unpack .../5-libzinnia0v5_0.06-3ubuntu1_i386.deb ...
Unpacking libzinnia0v5 (0.06-3ubuntu1) ...
Selecting previously unselected package mozc-utils-gui.
Preparing to unpack .../6-mozc-utils-gui_2.23.2815.102+dfsg-2_i386.deb ...
Unpacking mozc-utils-gui (2.23.2815.102+dfsg-2) ...
Processing triggers for mime-support (3.60ubuntu1) ...
Processing triggers for desktop-file-utils (0.23-3ubuntu2) ...
Setting up mozc-data (2.23.2815.102+dfsg-2) ...
Setting up libzinnia0v5 (0.06-3ubuntu1) ...
Setting up tegaki-zinnia-japanese (0.3-1) ...
Setting up libprotobuf10:i386 (3.0.0-9.1ubuntu3) ...
Setting up mozc-utils-gui (2.23.2815.102+dfsg-2) ...
Processing triggers for libc-bin (2.28-0ubuntu1) ...
Setting up mozc-server (2.23.2815.102+dfsg-2) ...
Setting up fcitx-mozc:i386 (2.23.2815.102+dfsg-2) ...

Edit: I was able to get it working with this guide.

(This answer from three years ago appears to have the solution I wound up implementing as described in my answer below, though I think fcitx is already installed in Lubuntu 18.10.)