[SPOILERS AHEAD]
She loved both Sou and Hina, and both of them really loved her too. But I feel like with Hinata there was something missing.
Hinata only kept a distance from Anna because he was afraid that Sou would get hurt. He was doing it for Sou. He didn't think about Anna's feelings. Sou did the opposite. He decided to put his own feelings aside because he kept Anna’s feelings on sight. Because he thought Anna would be happier being with Hinata, he supported their relationship. Of course he did it for Hinata as well (they were best friends after all), but the fact that he was always looking at Anna (even at a distance sometimes) was what touched my heart. He would always do everything thinking about her…
While Hinata was always running away from his fears (like when he didn’t tell Anna he liked her, when he was in a weird relationship with Mari-sensei, or when crazy Mari-sensei was back again in the story at his new school and he hided it from Anna), Sou was standing still, facing all his problems and fears. Even though it must have hurt him so much, Sou kept thinking about what would be best for Anna in every situation and doing everything he could over and over again. And even when he decided to keep a distance from Anna (which may seem selfish at first), he did it so she could work things out with Hinata, because he knew she liked him.
I wish the person Anna chose to be with was the one that not only she loved (since she loved both), but also the person who stood up for her the entire story. Sou was always there for her in the moments she needed, she was always his priority. He cherished her the most, so I was really sad for him at the ending.
I feel like Hinata was Anna’s first love, and like all first loves, he was really important to her and made a huge impact in her heart. But life happens and feelings change. And all that confusion in her head was that she didn’t realized what was going on yet. She loved Hinata first, they decided to become a couple and thinking rationally, she should be happy. But she wasn't. She liked Hinata for so long, fought so hard for him, and now that it was all settled, why wasn't she happy? Because after all the things that happened, Sou conquered a bigger place in her heart. Sou was her new love. Her feelings have changed and now she liked Sou the best. And I think the Manga ended right in the middle of her realizing all that.
