The search phrase breaks down into three distinct parts:

You can read Chapter 120 legally on the day of Japanese release via:

No "Weloma install" needed. The trade-off? You pay ¥340 per chapter or subscribe.

Title: The Calm Before the Storm? A Look at Kujo no Taizai Ch. 120 Platform: Weloma (Raw) Status: Raw (Japanese/Untranslated)

This is the "weloma install" portion of the keyword.

Note: Some antivirus software flags Weloma as a PUP (Potentially Unwanted Program) because it accesses local certificates. This is typical for decryption tools.

If the "Weloma install" process seems too technical or risky, you have three alternatives to read Kujo no Taizai raw Chapter 120: