Every time I hear that word I cringe with agony and fear. There is nothing more that I dread than summer in Japan. I come from a hot country but it's not humid like it is in Japan. The only other muggier place that I have been to is Singapore. In Singapore as soon as you step outside of the hotel you will be instantly drenched in sweat. It's kinda interesting though because in Singapore the air conditioners are on full blast and cold wherever you go. Also, they have turbo escalators in Singapore. I was really surprised at how fast the escalators are. You literally have to jump off at the top or bottom when you arrive because it's traveling so fast.
What are your ways to beat the heat? Years ago when I was dying from the heat, I found the greatest invention ever known to mankind, AIRism. I always wear undershirts and these undershirts are like magic when it comes to keeping cool in the summer. They are so light and airy it feels like you aren't wearing anything. I haven't tried the socks yet but I think I might this summer.
Another downside to summer is that it gets expensive to live in the summer. My electricity bill is three times as much in summer as it is in other seasons when I don't use the air conditioner. I tried to stick it out once with just using a fan but that didn't work out so well.
The one redeeming thing about summer is that there are fireworks festivals that are awesome. In Hawaii we have fireworks on the 4th of July and New Year's Eve but those shows don't even come close to the shows here in Japan; They only last for about 20-30 minutes. I really like getting dressed up in my yukata and wearing straw sandals. It's really Japanesey! ( Is there such a word? ) But the best part of the summer festivals is the food stalls and cold beer! I know the food from the stalls are expensive and not so tasty but I guess it just adds to the atmosphere. I have been to a couple of different fireworks festivals but my favorite has to be the Kobe Port Marine Fireworks Festival. https://kobehanabi.jp/
I hope you all have a great summer and stay cool!