From just watching the very first episode, I can tell this anime is going to be primarily about the relationship between Takagi and Nishikata. It appears as though Nishikata is constantly trying to find a way to get back at Takagi for continually getting the better of him only to wind up being outsmarted and outwitted at whatever plan he tries to implement. While it is shown that Takagi has romantic feelings for Takagi, it shows that she also has them in return but does not make them quite as apparent.
From the very beginning something I am quite fond of is the art style. Something I always love when it comes to anime is either heavy contrast of colors (think Hellsing Ultimate) or bright colors done with bright colors that gives off a “warm” feel (think Kyoukai no Kanata). Well, the overall aesthetic is something I can get into, especially since their heads are drawn bigger than their bodies and it gives off a sem-chibi feel when it comes to the characters (who are obviously children still in elementary school). The expressions and voice changes in the characters gives off an atmosphere that completely compliments the artstyle chosen.
While the plot is overall simple from what I am seeing, it is done in a way that will undoubtedly blossom into more in-depth moments that could possibly end up seeing Nishikata and Takagi as a couple by the end of the anime. The reason I say this is because Takagi is giving away small hints about her feelings (such as the eraser prank she played on him or encouraging him to go further when he begins to ask her if she likes him romantically). Though, because of their age range, it might be something more akin to a mutual-likeness that is acknowledged by both and is not acted upon since Nishikata and Takagi are still so young.
To be honest, I am quite interested since it seems the characters are close and teasing at a young age is often a sign of affection that children are unable to outwardly confess due to embarrassment and fear of rejection (which seems to persist throughout the school experience by some people). This anime is very cute, but could also become quite annoying or stale if the formula does not stay fresh throughout the entirety of this 12 episode anime; nothing to do now but see how that goes!