Kenseiden follows the story of Hayato, a samurai looking to retrieve five ability-granting scrolls and kill some evil warlocks. This involves battling through sixteen levels, including four rounds of impossibly difficult "training".
It's a prime infuriating example of fake difficulty, as Hayato moves incredibly slowly and there are generally an impossibly large number of enemies on the screen at any given time (especially bad in the training stages, where one hit sends you back to the beginning).
This version of the run collects all the scrolls and bonus upgrades (as opposed to the any%).