For reinstallation, I every time search how to clean install linux since I don't want to delete windows system.
I see /dev/sda, /dev/sdb, and /dev/sdc exist for my environment.
sda is main disc which means SSD (256GB) for me.
sdb is sub disc which means internal HDD (500GB).
sdc is flash memory for installation.
First time, I set sda partition as below.
/ 128GB/home 200GB
swap 32GB
FAT32 140GB
However, FAT32 is used for windows system, so when "Installation type" window (meaning, partition setting) appears, this FAT32 140 GB doesn't exist.
Be careful you delete only "/", "swap", and "/home" to reinstall by clicking "-" button.
Then, click "free space", and click "+" to create partition as below.
Size: 128000MB, Primary, Beginning of this space, Ext4, Mount point: /.
Size: 200000MB, Logical, Beginning of this space, Ext4, Mount point: /home.
Size: 32000MB, Logical, Beginning of this space, swap.
Then, click "Install Now", and "Continue".
Select location, "Tokyo".
I personally use US keyboard, so I select English (USA) for keyboard setting.
Put your name and computer name as what ever you like.
Encrypt or not? It's your choice. It's personal use for me, so I don't encrypt.
OK, start installation, and reboot.
After rebooting, first open "terminal" and type
$ sudo apt-get update
$ sudo apt-get upgrade
Then, start setting of languages or some other options.
Below is recommended.
Update Manager: change the server to Japanese ones. I use JAIST and Tsukuba servers.
Input Method (Japanese): Fcitx