|You've heard of fanservice... this show introduces catservice.|
A major theme here is what it really means to do something with good intentions, even when the end result is not the best. Moderate spoilers follow after the jump.
In elementary school, Kyotaro overheard some teachers grumbling about having to celebrate the birthdays of the kids that month. He didn’t really care about having his birthday celebrated in the first place, and knowing that the teachers’ hearts weren’t really into it only put him in an even more sour mood.
In the current time, the Library Club dresses up to promote a cafeteria event, and meet Senri in the process. They try to get her to help out, but Tsugumi ends up saying how having the Song Princess doing promotion would really help things out, which hits a nerve for Senri and makes her think that even the group’s kindness to her when she was sick in the previous episode was only out of recognition of her title.
Thankfully, Kyotaro is able to convince her to trust Tsugumi’s good intentions. After all, he can sympathize with Senri’s distrust of intentions, as he himself believes that much of the time, people's good intentions are just hypocrisy, such as with those elementary school teachers. However, he feels that Tsugumi is different. He feels that behind Tsugumi’s good intentions are a genuinely good heart—something he cannot quite understand himself still, but which has up to now compelled him to stick with her to try to learn why she does what she does.
There’s a common saying that “the road to Hell is paved with good intentions”, which is a recognition that many times, people with good intentions end up doing bad things, even to the point where it corrupts their very being. The Well-Intentioned Extremist (trope!) is a great example of this. And even when good intentions aren’t leading to bad things, people can often sense when someone is just going through the motions of doing good.
That is why having a good heart behind good intentions is important. This is why a major part of Christianity is around changing our naturally wicked hearts toward becoming loving hearts, rather than just doing good deeds (although doing good deeds can be part of the process). When good intentions are backed by genuinely good hearts, even if the end result is not the best, things will usually work out for the better one way or another.
That's not to say that good-hearted people doing things with good intentions are immune to doing some bad things, though. Tsugumi had this happen to her when she tried to tell her hospitalized younger sister about Shiomi Academy and how she has a lot of friends there and has a fulfilling life there, even though back then this was not true. She ended up continuing to lie, and hated herself for it. Still, there's something to be said for her ultimate solution to the problem, which was to start the Shiomi Happy Project to try to make her lie a reality, showing how she can even take an otherwise bad situation and turn it into something constructive.
In the end, perhaps the most important thing is not having a "good" heart, but a "growing" heart. Our hearts will always have sinful tendencies as long as we are on this earth, but as long as we continue to seek towards becoming truly loving people, even if we stumble along the way, we can pick ourselves up and continue to do things with truly good intentions. And when good intentions are backed by hearts truly seeking good, people will notice, and their hearts might even change as a result. Kyotaro discovers this when he goes to let Tsugumi know that he does not plan to help her after Golden Week... only to find that she and the others have been planning a surprise birthday party for him. This display of genuine goodwill (as opposed to the obligatory celebration from his school days) moves his heart and convinces him to continue with the Happy Project.