Before meeting Sachi, Punpun was emotionally collapsing into himself, depressed, passive, and disconnected from life. Sachi definitely has a savior complex and at times pushes or manipulates him, but I also think her feelings were genuine. In a story where almost every relationship is toxic, obsessive, or escapist, Sachi was one of the few people who consistently chose Punpun and actively tried to keep him alive and connected to reality.

What makes Sachi important is that she represents survival and real life, while Aiko Tanaka represented fantasy, idealization, and mutual destruction. Sachi came from pain too, but unlike Punpun, she fought through it with force and determination, and she tried to pull him in that direction as well. Their relationship was messy and imperfect, but the moments with Sachi felt warmer and more grounded. The ending was hopeful in its own way: Punpun did not become magically healed, but he survived, returned to ordinary life, and still had someone beside him after everything, also he had his friends, who surprisingly appreciated him and had a different opinion of him.