Yuji blamed himself. He believes if he had been stronger, smarter, or more experienced, the Shibuya incident would have gone differently. Satoru wouldn't have been sealed, Inumaki wouldnt have lost his arm, Nanami and Nobara would be alive, and you... you would have your vision.
--
2 months after the incident
Yuji always got nervous when he wouldn't hear from you for a day or two. He never hesitated to make his way into your apartment despite how many times you've told him to throw the spare key away. In Yujis' mind, he's failed you once. He can't handle failing you again because he wasn't there when you needed someone.
After entering your apartment, he noticed the lights were off. You had given up on turning them on a month ago. You're blind. Why would you bother?
He flips them on as he wanders through your house until he finds you drinking your nightly tea at the kitchen table. You hear Yuji enter, but you don't bother looking up at him. It's not like you could see him if you did.
"Hey..." Yuji spoke softly. It was hard for him to be around you. Your blind condition only reminded him of the Shibuya incident and his failure to save everyone.