Daniel LaRusso has not been a good husband to his wife Amanda, and Cobra Kai season 4 needs to address his past behavior. Daniel and Amanda's marriage has faced adversity on the hit Netflix series, with some fans expecting Cobra Kai season 3 to see the two split as a result of his actions. While this proved not to be the case, season 3 did see Daniel meet up with an old girlfriend in Okinawa — something that is bound to come back and bite him down the road.
Cobra Kai follows the adult life of The Karate Kid bully Johnny Lawrence 34 years after the events of the '80s film franchise. When the show begins, Johnny is in a rut, having never really moved beyond his high school glory days; now in his 50s, the once-popular rich kid bad boy is living a sad, lonely life. The former rivals Johnny and Daniel cross paths again decades after their previous conflict — seemingly by accident but perhaps by fate — which inspires Johnny to clean up his act and reopen Cobra Kai.
Cobra Kai has focused on subverting expectations by destabilizing the good guy/bad guy binary between Johnny and Daniel. While Daniel was positioned as the protagonist/hero in the Karate Kid movies, the sequel series puts him in the villain role, allowing viewers to empathize with Johnny's position. Daniel's relentless attempts to shut down Cobra Kai come across as mean-spirited and unfair, and while he maintains the same good intentions that marked him as heroic in the '80s movies, Daniel's circumstances have changed so much that he is no longer the underdog audiences root for — Johnny is. By the end of Cobra Kai season 3, Johnn and Daniel have largely settled their conflict, but the series has not fully dealt with another significant interpersonal issue set up in previous seasons: Daniel's marital problems.
Throughout Cobra Kai, Amanda has been the long-suffering wife who is increasingly annoyed and frustrated by her husband's self-serving, inconsiderate behavior. Daniel's obsession with shutting down Cobra Kai harmed their business, their marriage, and their daughter's reputation (and safety) at school. After the dramatic showdown in the season 2 finale, Amanda was furious with Daniel — seemingly setting up a separation for season 3. This did not happen, and instead, the two appeared to reconcile, thanks in part to Daniel's renewed efforts with their shared business, LaRusso Auto Group. Amanda even experienced John Kreese's evil first hand, giving her a new perspective on, and understanding of, her husband's concerns about Cobra Kai.
Daniel went to Japan in Cobra Kai season 3 to attempt to salvage a business relationship with Doyona International. After failing to convince the board to continue their previous arrangement, he headed to Okinawa, which is the setting of The Karate Kid Part II. Although he doesn't go there with the intention of meeting up with his ex-girlfriend Kumiko, the two do have a fateful encounter — and this is where Daniel firmly enters "the Danger Zone." In one telling exchange, Kumiko notes that she never got married because no other man "fought to the death" for her, and Daniel's blustering response suggests that mentally, he is not being completely faithful to his wife (at least in that moment). Nothing happens, but there is an unmistakable sexual tension between the two, and it is never made clear if Daniel tells Amanda about the date.
At the end of Cobra Kai season 3, Daniel also runs into his other ex-girlfriend: Ali Mills. The way Daniel and Johnny squabbled in front of Ali was largely played for laughs, as both Amanda and Ali were clearly disinterested in assuming any sort of rivalry with each other (unlike the men). Yet, it continued a trend that Amanda on some level must be aware of. There are several instances in Cobra Kai in which Daniel appears to go behind his wife's back, either because he omits certain details about his actions or simply doesn't follow through on his promises. It's only a matter of time before the shrewd businesswoman figures out what's really going on — and when she does, Daniel may find himself in a fight he can't Crane kick his way out of.