Even though I have only watched the anime and not read the manga, this is only an opinion of my thoughts on Tsubomi at the moment. I'm not sure about you guys but I kind of dislike her as a character: she always seem to be the extremely popular one who is always the centre of attention and reject the ones whom she thinks are on a "lower" status than her, as shown when she rejected Mob. Honestly, I don't even know why Mob even has a crush on Tsubomi, he could have gone with any other girl who actually LOVES him!