Senko-san belongs to a very specific sub-genre of slice of life, I believe it's called "iyashikei" (thank you google) which roughly means "healing." The purpose of the show is less to tell a story, or even be a time killer, and more just to relax the viewer, soothe them, help them let off stress - exactly like our titular Senko is doing for our protagonist Nakano.
Watching this show is a simple, sweet and wholeheartedly pleasant experience, but if you're looking for engagement, for action, for depth - this is not where you will find it.
And that's okay. Sometimes, you just need a break. Sometimes, you just need some Senko-san.
