Also, 4e books are super pretty.
I've run a few campaigns of L5R and, yeah, there's a lot of lore to dig through but like a like of games with rich settings it's very much a matter of which parts you think are cool and important to focus on more than anything.
Often the problem I ran into when coming up with ideas for L5R games was time periods; the metaplot kind of 'starts' around the tenth or twelfth century and then shit gets crazy. So a common technique I had for running games was setting it a couple hundred years ahead of "canon" in a time of nebulous and uneasy peace between all of the Clans, save for the shit I wanted stirred and some of the "fundamental" conflicts (the Crab and Crane hate each other, the Unicorn are weird, the Spider twirl their moustaches etc).
Alternatively, a campaign model I came up with that might be useful revolves around picking one tiny lore strand and saying "fuck the rest of it". This lets you focus tightly on one particular aspect of the setting without getting too overwhelmed. One game I came up with using this principle went like this:: A Minor Clan called the Bat Clan are created relatively recently in the history as thanks to a shaman; the shaman channelled the spirit of the Emperor's sister, allowing him to get closure and say farewell. The shaman, Koumori, is given a previously-uninhabited tropical island in the Islands of Spice and Silk to call his own and set up his castle. The game was about the foundation and establishment of this small clan on a hostile island whose woods are full of carnivores and worse - for the reason Koumori chose that island in particular is because the wall between realms are thin and spirits are common. So a lot of the conflict started very human and small-scale, people struggling to survive in a new place and building relationships, then worked in some more abstract notions of "proving themselves" and carving out the clan's wider identity and role, and then further into the setting's cosmology through the Spirit Realms. But being on a small island out in the ocean we didn't get into inter-clan politics, the Shadowlands and so on.
