usually i tend to hate when a love triangle is added, especially when it tends to be a lazy resource to extend the series, HOWEVER, i find this probably one of the few instances it might work.
Reason is, depending on how it goes, it can help to ground tama's attitude and behaviour towards him, since it's a very one sided situation most of the time, having someone that could take him, especially when not even himself has a romantic connection with her yet, for her to realize that how she behaves goes to the extreme with him.
it's an interesting setup, because usually it tends to suck, but since the characters aren't in a relationship yet and are still far away from one, it can and likely, will help for them to get there, it doesn't have to be deep, but with how she behaves, a rival is needed for them to actually progress, otherwise they would get stuck in a loop.
TLDR; they need something to shake things up so they can progress, and this is a good way to do it.