@Vrizu I think you are forgetting about chapter 152. The screen you posted shows what Sensei & co. think about her after hearing her shipping Akari and Kiriyama, which was a reasonable thought, but It's not an absolute truth, just what they thought.
In ch 152, Hina's friend tell her that it's pretty obvious she likes Kiriyama and we get to see her inner monologue which shows that she is just scared. People kept leaving her since she was a kid (her father, baseball guy etc.) so she fears she may not be able to keep Kiriyama around, while her sister (which is basically her role model) may be able to do so. The fact that she cries while saying this imo means she really doesn't like the idea of them being togheter and she's probably aware of her feelings to some extent but she'd rather see Rei togheter with Akari than seeing him leave.
It's a pretty silly thought, but understandable given her past and her age. I don't think she was ever oblivious about love, that was just Sensei's and the others thought.