Sadly in Tokyo, most businesses post their info to twitter or instagram, but in both cases you're able to read without an account (not well, but it's possible).
I had a similar experience in Osaka. Prettry frustrating. Actually, I didn't know that you can read the posts without an account! That's good to know!
Instagram makes it extremely frustrating without an account. Many times I have checked a small business's opening times on Google Maps only to arrive and find them closed... the only place they reliably post their times is on Instagram.
I gave up and got Instagram.