@Pyoro It is relevant. It provided the background about Japan's relation with other countries, the self-defense force and their air force which lead to why Asa was brought here. The Olympics is the symbol of peace showing that Japan has changed its way but that leaves them in a tight-spot. They can't attack the monster.
@miyako19 Historical knowledge the reader should be familiar with or that could have been better woven into the background of the plot instead of essentially just info dumping it in this chapter. Mind, I'm not saying it was awful or anything, I'm just saying I don't think it's perfection incarnate. ^^
Remember the first chapter shows the Monster (prob Godzilla) at the 2020 Tokyo Olympics. It's likely that this entire series was commissioned because of that event, so exposition about previous Japanese Olympics is to be expected.