Yakumo is funny in her own way xD
She also brings out a different side of Harima, since she is his only trusted friend. He's nice and sweet and well behaved with her; a side we as the audience know exists, but he rarely shows to others.
That's why I appreciated the love triangle between Eri, Yakumo and Harima. Even so I like all three of them and would prefer them unhurt, their theme and chemistry with Harima are vastly different and let him shine in other ways
