Eri had taken it for granted that Fuyu would be by her side regardless of where she goes in life, often disregarding the efforts of Fuyu to make her happy that she could have noticed, and has increasingly been thrown off by her relation with Senpai.
Fuyu has been hiding a lot of how she's been feeling from Eri for fear of affecting their relationship, and thus feels betrayed that Eri's love doesn't extend to her as hers does to Eri in withholding her hurt (in a perceived selfless vs selfish love dynamic).
Fuyu coming clean not only makes clear to Eri that she had been taking Fuyu for granted but also makes her feel selfish for her reaction at the festival, given what Fuyu reveals she's tolerated for love (though admittedly I think her immediately coming clean was probably the healthier move by comparison).
Fuyu realises that she's overly burdened Eri with her own actions and blames herself for selfishly loving Eri and hurting her, and Eri also blames herself for taking Fuyu for granted and not noticing the pain she was inflicting upon her, believing what she had called love falls short of what Fuyu deserved from her.
tl;dr they've hurt each other unintentionally and both feel undeserving of the other as a result
Well whaddaya know, communication actually happened for once. It's all out in the open now and that's good, even though this is really painful for them. Now we can take a step back and then start moving forward.
Eri was caught doing intimate things to Kyou Chan, and her eyes were like dead fish lol, and she still didn't know her feelings and chose the word "friends again" ..,I hope Fuyuki gets a new life with her senpai
Thank you for the scanlation! I wanna say there's page order that got swapped. Page when fuyuki says "I love the most in the world" or something and when eri says "i see"
I've never been so happy and in pain before. Thank you, kurumiyoshizawa for bringing back peak. My heart hurts now, but at least we're getting somewhere with Eri and Fuyuki!