Nobody makes you care about kendo the way this does. The animation moves like actual swordwork, economical, precise, alive in ways that make every strike feel like it costs something. There's no melodrama here, just the quiet satisfaction of watching people get better at something difficult, told with enough humor that you're laughing at the absurdity before you realize you've learned what kendo actually is.
Kentoushi is a sports OVA released in 1990 and running three episodes. Its story comes from a manga by Kurashina Ryou that carries the same title.