In response to a string of burglaries in the apartment complex, Kramer decides to protect his valuables in the Season 9 episode "The Strongbox," acquiring the eponymous object. While this is one of Kramer's more sensible decisions in the entire series, the lengths that Kramer goes to hide the strongbox's key are decidedly more nonsensical. However, the biggest flaw in "The Strongbox" is that Kramer's arc in the episode isn't particularly funny, serving a narrative function throughout the story rather than a comedic one.
There are definitely funny moments throughout "The Strongbox" but Kramer isn't central to any of them, existing more on the periphery to drive Jerry's story forward. From planting his strongbox key in inconvenient places around the complex to agreeing to help Jerry raid a pet cemetery, Kramer doesn't really get much to work with on his own in the episode. There are plenty of "Seinfeld" episodes that underutilize Kramer, but "The Strongbox" makes this flaw more glaringly evident given his role in Jerry's plot line and the episode being named after Kramer's acquisition. A missed opportunity of an episode, "The Strongbox" noticeably gives its breakout character the comedic short shrift and is all the poorer for it.
