Man. I loved this chapter, it even made me teary-eyed.
Sanako worked really hard to help those girls from the art club of her own volition even though she had nothing to gain from it, which follows up on her speech during the VP election - she did actually start to see other people as people.
Then she also correctly recognized when she's unable to help the two art club freshmen just by herself and asked the Prez for advice. And at the end, she made a strong impact to the art club, improving her reputation at school bit by bit.
Most importantly, she proved to herself how she can do things properly and be a productive and helpful member of society; self-worth is something she sorely lacks and she made tremendous progress on that front.
Great chapter.