In Chapter 2, seeing all the students come together to try and fight the cabin fire.
Ibuki's relationship with Togami, especially in the bonus chapter which goes into detail about her crush which shows she couldn't care less about his status as the "ultimate heir" not only does she forget about the wealth and power the Togami family has until Akane brings it up and when she has her Love Epiphany every single trait she realizes she loves about "Byakuya-chan" is exclusive to the imposter, not the man they are pretending to be. Hell she even got their Byakuya persona to slip for a little while.
Seeing how supportive and accepting all the girls are when Ibuki tells them about her crush is touching too since not even Saionji tries to tease her about it while Koizumi's complaints are quickly ignored in favor of their friend's happiness.
Ibuki standing up to Koizumi for Togami's sake after he steps down as leader.
Ibuki gets another one in chapter 3 part 3, where she decides to try and bring everyone out of their despair by making a mini summer festival, complete with a fireworks display and personalized custom yukatas for everyone.
The festival itself also counts in the following chapter.