Plastic Tree is having an Ameba Studio broadcast (details here).
Please notice that you do not have to pay for the regular broadcast (19:00~19:30). You only need AmeStu points for the premium broadcasts.
It’s been a really long time since I’ve used Ameba, and the website has changed a lot, but I’ll do my best to help out.
1. You need to sign up on Ameba. It’s not terribly difficult, even if you don’t know Japanese, since the format follows typical registration on any other website. In case you need some help, here’s a guide in English (with pictures). It tells you how to sign up for the game Ameba Pigg, but the first few steps are for signing up on Ameba in general.
2. Alright, so you have Ameba now. Go to Plastic Tree’s broadcast and click 「ログイン」at the top. Input your sign-in information, then it will prompt you to connect your account to Ameba Studio. It will be the button in the middle of the screen after you log in.
3. Now your account is linked to Ameba Studio. And if you go back to the Plastic Tree broadcast page, you should see that a green box with a pink button has appeared on the left. This is where you’ll buy AmeStu Points. These points are necessary for watching premium broadcasts. 50 points = 1 minute of viewing, so 1,000 = 20 minutes (there’s a 1,000 point bonus for using credit cards for the first time). Apparently you can also earn points by playing Ameba Pigg, but I don’t have any experience with that. Choose your payment method and follow the steps (if you need help, just screenshot your page and I’ll translate it for you).
4. At 19:40 JST (the premium broadcast), you can click the grey box with the round arrow on Plastic Tree’s page to watch. Be aware that it’s first-come first-served though. Plastic Tree’s regular broadcast is from 19:00 to 19:30, and I’m not sure if you watch it from the same portal or not (I’ve never used Ameba Studio before). The regular broadcast is free to watch, and in case you can’t get to it via that page, try it here. It even has a schedule of the broadcasts with the time in your timezone.
I hope that’s enough help for those interested in watching this broadcast. If you have any questions, feel free to ask me and I’ll try my best to help.