Kimi Wo Hitori Ni Shite Agenai

"I won't let you be alone."

Chigusa, who struggles to express herself, ends up building walls between herself and other people. She's always alone at school, until one day a stunningly beautiful boy transfers to her school. To Chigusa's surprise, the boy turns out to be Iroha, the only person she ever considered a friend in her childhood. Iroha tells her that he changed schools just to see her. He effortlessly crosses the walls Chigusa has built around her, steadily closing the distance between them.

(Source: Kodansha, translated)