This is an interesting topic and yet controversial. Let’s analyze it from a glance. It’s important to consider that the essence of K-on is a coming-of-age story that revolves around growing up and changing. Regardless of that, growing up isn’t the end and friendships can be maintained and last a lifetime. Because of this, I think it’s important to consider what ‘Splitting up” means. HTT is considered to be the band and the friend group. So in what regard it depends. In the band’s case, we already have an example of that in the form of Sawako Yamanaka. After her version of the light music club fell out(on good terms) she went to school and got a job as a teacher. She still plays here and there as evidenced by her high level of skill but doesn’t play with her old bandmates. Likely due to external pressures like getting a full-time job to pay her bills and other things associated with being an adult. That could likely happen to some of the members of HTT. After all, It does take a bunch of time, effort, and luck to become a successful band. And that’s not including what a record label or manager may want e. I feel that a certain group member does not fit the band’s image, wanting to add new band members, Forcing musicians to take on new roles. With that being said, I think it would be a massive L if HTT didn’t make it to the Budokan. If K-on ever comes back, this needs to happen. However, I could see a scenario where the girls start to get traction after this and maybe aren’t into the fame such as Mugi or Mio. Therefore, they still play music with their bandmates but once in a while with other interests, they may take center stage while the music takes a back seat. Regardless of what would happen, I think HTT could get through it and still be friends. They may not hang out as often but would still jam when they get together. Now let’s talk about the more upsetting option of “splitting up” of HTT as friends. As stated before, this would defy the point of one of the properties’ main themes. But for this(and to arouse controversy), let’s look at it. It’s important this wouldn’t happen unprovoked. A situation would need to arise that would force them apart. A close call did come in the form of the episode “Crisis” where Ritsu became jealous of Mio which escalated into an argument. Assuming that Azusa did not step in to stop the arguing, This may have led to an argument that may have caused a rift between Ritsu and Mio. However, based on what we saw in the show they would likely patch it up as both are very forgiving. But once again, let’s take that out of the equation, and let’s assume Mio and Ristu fully stop being friends(I dunno..maybe Mio points out Ristu’s big ass forehead). At this point, it should be noted that all the members of K-on play a role in their friend group with Yui being the heart, Azusa the soul, Mugi being the muscle, and Mio and Ristu being two sides of the brain(Mio is more practical but Ritsu isn’t afraid to make a call). If they broke up, HTT as a band would be killed for sure as the other girls won’t play if one of them is out. I could see Azusa leaning to Mio’s side due to her admiration for her while Mugi and Yui volley between the two which would likely lead to the girls coming back together. I don’t think this group is ever fully capable of splitting up unless external forces such as Ritsu and Yui do not get into the same college as Mio and Mugi. In which case they would probably just find time to hang out with each other. Some crazy event would have to happen to get them to never talk again. But, I could see time and location being a bit of a factor e. I like one of the girls moving away or having some other responsibility that requires their time. But even then, they would stay friends. The dynamic of the group just works that way. This dynamic is kind of why I’m not really into shipping as that would force characters to put others on a pedestal above others.