It's very, very easy to follow. Firstly, dudes only work about 10-15 singles matches a year. Those will all be at the PPVs and the tournaments. G1 Climax, which is happening right now, and the New Japan Cup which happens in the Spring. Otherwise, they're in tag and six man matches with their factions in matches building up to their big singles showdowns. Most MAJOR storyline shifts happen after matches on PPV so you can see them happen. With so few singles matches, every match can be a reasonably big deal, and it's easy to keep track of and remember the happenings.
And then to follow what's happening on the house shows and storyline developments, there are a lot of good blogs to post all the results, and even better, have summaries of the storyline stuff/translations for what's happening. Of course, these are spoiler heavy.
http://www.puroresufan.com/njpw/ is the go-to for New Japan.
The thing about
good puro booking. Is that things flow and develop for years. It's a complete 180 from WWE where you're SUPPOSED to remember what happened six months, a year, two year, three years etc etc etc ago. Every time guys come across each other, it's another chapter in their story. If you just hop into stuff now, you'll find it super enjoyable of course, but occasionally you'll wonder why the crowd is going apeshyt at something that didn't seem THAT epic, and that's because it's some sort of callback to a spot or a moment that happened before. I'd really suggest watching the Okada-Tanahashi matches in order to
really appreciate them. It starts with Tanahashi being overwhelmed by this young guy who can exceed him with the athletic style he brought to the puro game and not being able to respond to someone who, for the first time, he just couldn't out-work for a W. And then they develop the story perfectly until their final match 18 months later.
There was a really fun match between Karl Anderson challenging Tanahashi for the belt early last year, when Anderson pulls out some of the signature moves and spots of some past NJPW gaijin like he was channeling their energy to pull off the upset the crowd ate the shyt UP. He had a Japanese audience legit yearning for a foreigner to beat the biggest star in the country.