Okay, so this is what I understand from this sequel, Towada and Haru-senpai are dating, Towada is friends with Suzuki and are also classmates. Towada and Haru-senpai are both in love with each other if you will re-read the first installment of this story. But in this sequel when Towada found out that Suzuki actually "liked" Haru-senpai, I guess she was hurt and felt liked she was just being used to get close to Haru-senpai and their friendship wasn't real, but in truth Suzuki actually like Towada.
So in conclusion, I think that this is a one-sided love of Suzuki with regards to Towada. (Just check Towada's reaction on the first page of this sequel) Also note the step Towada deliberately took with Haru-senpai on the first installment, which was unexpected with her personality.