Ok, its been 5 years, I'm back, I get the ending a bit more. Timeline confused me a bit. 5 years in the future I'll definitely have understood everything
All the people saying "Her fault cause she broke that casual relationship they both wanted, anyway she was going to dump him"
Relationships change, that's the point of dating. Refusing that change is basically refusing the relationship itself. She wanted him closer, and if Gen had reciprocated...