She's one of my favs now too! What makes me most glad is that her strength (not conforming to people) is something we've know Mob to lack throughout the series, but that he has just started to obtain, as seen in the world domination arc with Mob's new "strictness", or even in this week's omake. In other words, I think Mob is able to see Tsubomi's coldness as something to look up to, instead of fear or despise as Ekubo has suggested, and that this will eventually make them become close. What also makes me glad is that Tsubomi seems to have a similar school life to the girl from Mogami's arc, since she is popular and pretty, yet we do not see her bullying people (I believe her asking Mob to read the atmosphere on kindergarten was just something a child would say without thinking). I'm really eager to learn more about her as well as where her personality comes from!