niconico is an absolute nightmare, basically i can only watch VF streams live and while I'm logged in.
I used to host the Tokyo Bay Area Cups on my channel until GAME Newton switched to niconico. But there's ~40 hours of competitive JP VF if you want it.
http://www.nicovideo.jp/?header
For VF Search: バーチャファイター or you can just search: vf5 or vf5fs
For SF4 search: ウルトラストリートファイターⅣ
*Note that to the left of the search bar there are 4 areas you can search through. The first, which is the default, is videos. The 4th one is live streams.
I prefer setting the region and language to Japan because most of the comments and users are from Japan.
Once you have searched:
The drop down text is to sort the videos. The first one (highlighted) is "new comments." The 9th one down is to sort by "the newest upload." I like to use the first one all the time. Click on the 4 boxes to the right so you can see all of the videos in rows of 4. It makes it easier to browse.
This is how to favorite a video. I click the big box and a bunch of smaller boxes show up. Click on the + (the left furthest + box) and a small window will appear. Towards the bottom you can click on two things. Click the one on the left to add to "my list." The option on the right is to cancel. The window will close by itself.
To go to your favorites:
If you just want to know when there are tournaments/events or even which streams are on at a particular moment just go to
http://kakuge-checker.com/
That's the go to site for Japanese fighting games. They have a list of current streams both in Japan and overseas. They also have a calender for any fighting game event. To get to the calender click the 3rd link (2nd to the right of "Top") and a list of japanese text will apear. Click the first one. This will take you to the calender. Or you can just take the shortcut
http://kakuge-checker.com/event/list/
It should be easy to navigate the calender as there is a logo next to each event. The time is obviously in Japan.