I knew it... after reading this author's other works, I just knew it's going to be like this.. Yet I still read their creations, hoping it'll be different this time. Nope, it is not.
Tatsuki just went back to his original goal before falling in love with Aoko. He got his heart broken and that's probably why he decided it best to just focus on expanding his art by focusing on it and leave for good. He's heartbroken but respects Aoko enough to completely calling it off instead of keeping some vague sense of hope in the both of them. He's moving forward with a clean slate.
Aoko... sigh..... I hate how her character is being assassinated by the author. She's using a lot of "me me me, I I I" in her rationale. "Setting Tatsuki free". "I like his art". "I am a burden". "He can go because I am not holding him back." etc etc. Woe is me but this is all for the sake of him. No. This was all for her, because she can't win against her own insecurities and paranoia.
Never once did she actually sit down to discuss with Tatsuki for the best course of action.
I get that she was so hurt and traumatized by the fucking bear. I understand how the little voices will pile up and get the best of you. I understand the darkness and how it's not easy to voice your insecurities and vulnerability, especially to the person you don't want to lose.
I'm frustrated because this is a fictional story. The author made a conscious decision to make Aoko this way.