Jeff Osaka’s twelve derives its name from its focus on monthly menus that highlight seasonality as far more fluid than just spring, summer, fall and winter. Seasonality wasn’t all that hot when Osaka opened twelve in late 2008; neither was the Ballpark neighborhood, where he turned an old storefront into a spare, elegant dining room laid out with nicely spaced tables and anchored by a giant antique mirrored bar. The vintage-theater-like marquee out front does little to suggest the eatery within, and the location has been a challenge from the start. But slowly, Osaka won over the city. Denver’s chefs became his first big fans -- Osaka has been a tireless cheerleader for the scene – and then Denver diners caught on to the undeniable delights of twelve. This is an intimate spot with a tightly edited, protein-centric menu that glides through the seasons, with five new appetizers and six new entrees designed to capture the spirit of the month. The service is almost as seamless, with Osaka himself sometimes pitching in to serve.