Pfft, I think this comic doesn't know how big money really works, lol. A measly $3.6B is nothing for Japan. The budget for the Tokyo 2020 Olympics has been pegged at US$12.6 billion.
We don't like the barrier s rank personality but we can't deny how cool and powerful his power is and he knows it. And it's true you will need to use a very big sum of money to protect the whole country from such a dangerous gate (it's in the city unlike the ant island) especially since they're using outside powers (foreigners). I think it's reasonable as a temporary solution. They can I try collect more offensive and support s rank and national rank within 1 year to clear the dungeon
@kaumrebahan even if its a joke its pretty common on korean and chinnesse manwha to shun or despise japan as a country, even if they like some of their art or culture, so more often than not they make them weaker or stupid, there must be some sort of propaganda on schools or from the elderly to make new generations mantain that hate.