https://rugby.byu.edu/blog-tags/seki-kofe
He signed up for classes at a JC right out of HS, but withdrew before attending a single class or paying any fees. However, it still technically started his eligibility clock. He then ended up working for a bit, then serving a mission before eventually enrolling at BYU. When BYU coaches checked on his eligibility, the JC enrollment didn't show up. As far as they knew, BYU was the first school he ever attended after high school. Certainly Seki knew he never attended classes anywhere else, so it never occurred to him that his eligibility clock was already ticking.
How someone at Cal was able to dig up Kofi's aborted JC attempt raises a whole bunch of questions.