Japan's Foreign Ministry has officially summoned and lodged a strong protest to the Chinese Ambassador. The details surrounding the cause of the protest have not been specifically outlined in the headline, but such actions typically occur when disputes in international relations arise, often involving issues like border conflicts or international policy disagreement. The time, place, and further context would require supplementary information not provided in the headline.

In Japan, diplomatic relations hold great significance, especially with its neighboring countries. A strong protest indicates a severe disagreement or violation that warrants the country's stern response. Respect for international law and fair negotiation is highly valued; this headline suggests that the local population perceives those values as possibly infringed upon.

Similar scenarios in the U.S. or EU might involve summoning ambassadors to protest significant policy disagreements or breaches of agreement. It's a conventional diplomatic way to express discontent or to request changes in a counterpart's actions and is not unusual in international diplomacy.