WARNING: The following contains spoilers for Episode 8 of Koikimo, "The Person I Love Is...," now streaming on Crunchyroll.
New for the Spring season of anime, Koikimo follows the story of a girl named Arima just trying to live her best high school life. But her best friend's older brother, Ryo, is absolutely infatuated with her, despite the fact that he's 10 years her senior. The story unfolds from there, following Ryo's antics as he tries to capture Arima's heart, only to be rejected each time. But in Episode 8, a clear rival for Arima's affections appears: one of her classmates, Tamaru. While Koikimo is all about Arima's growing feelings for Ryo, Tamaru poses a very real threat and may actually be a better match for her.
Ryo is a successful salaryman who hasn't been in high school for a long time now, so at first glance, his adoration of Arima is creepy. But as the anime progresses, it becomes clear that his feelings are genuine and getting stronger as he gets to really know her. The comedy of Koikimo rests in the fact that Arima does not want his attention, at least at first. Ryo begins to gradually grow on her. But there is still quite the age gap between them, and for a girl who hasn't dated before, this could make or break the relationship.
Now there's a wrench in the mix as well -- Arima's classmate Tamaru has realized that he also has feelings for her, and some strong ones at that. But it's not just their age that makes them a better match than Arima and Ryo. Tamaru and Arima have things in common in ways that Ryo simply does not. For example, Arima loves this one anime/manga series and she asks Tamaru to borrow the next volume and Ryo feels threatened because he doesn't share this interest with her. While Ryo does commit to learning about her interests and even becoming super into anime as well, he still is forcing it on her behalf. Tamaru doesn't have to -- he naturally already likes what Arima does.
Another reason that Tamaru would be a better boyfriend to Arima is that their romantic experience is relatively the same. Ryo is a known womanizer who can't commit to an actual relationship, which is a daunting thing for someone as inexperienced as Arima to deal with. Every time she thinks about him, she thinks about the fact that he's been with dozens of women who are older, more developed and more experienced than she is. There's a huge imbalance between them in that respect. Ryo acknowledges this imbalance but doesn't see it as a problem. But Arima does.
Koikimo is obviously setting up the gradual relationship between Arima and Ryo as a kind of reluctant romance. But Tamaru is a very real rival for Ryo, if Arima chooses to see him in that way. While Episode 8 does suggest that Arima is starting to develop feelings for Ryo, Tamaru is arguably the better match for her.
He's her age, they share the same interests and it's more of a level playing field. Arima will ultimately choose whichever partner she truly wants in the end, but Tamaru is now taking on an uphill battle against Ryo. Even though Tamaru is clearly the better match, he's faced against a man who has a decade of experience over him.