Japan has spent more than ¥4 trillion on the decontamination effort so far. So it's definitely not true that they have spent more on propaganda than "actually dealing with the problem".

> Total decontamination costs have exceeded 4 trillion yen as of the end of December. Going forward, additional costs are projected to grow by trillions of yen. [1]

Is ¥70 billion a lot? Sure. But to put it in perspective, more than $14 billion (¥2 trillion) was spent on federal election campaigns in the US in 2020 [2]. Gaining public favor is expensive in a democratic country. And misinformation is a real problem with real costs (e.g. to Japan’s fishing industry) - so it makes sense economically as well as politically.

[1] https://asia.nikkei.com/Spotlight/Fukushima-Anniversary/Fuku...

[2] https://en.wikipedia.org/wiki/Campaign_finance_in_the_United...