Google could already react to this
Google is suspected of violating competition rules in the distribution of digital advertising, as stated by the Fair Trade Commission of Japan.
Specifically mentions Google's restrictions on Yahoo's LINE company. Yahoo partnered with Google in 2010 and uses Google's search engine and paid advertising distribution system, which is shown to the user after forming a search query. In the mid-2010s, Google asked Yahoo to stop distributing search advertising for mobile devices on the portals of its business partners.
Yahoo complied with Google's request because the company was worried that if it refused, it would no longer be able to use Google's search engine. The Fair Trade Commission of Japan considers that such actions amount to unfair trade.
As Nikkei writes, Google may have already withdrawn its demands against Yahoo and has provided the commission with a plan to strengthen enforcement measures.