Animesmerize

"Confession"
Makoto Itou is a first-year high school student with a crush on Kotonoha Katsura, a girl who commutes to school on the same train as him, despite the fact that he has never spoken to her. When Sekai Saionji, a classmate of Makoto’s, sees a picture of Kotonoha on Makoto’s cell phone and realizes Makoto’s feelings, she decides to help Makoto win Kotonoha's heart. She becomes friends with Kotonoha and arranges a lunch between the two of them and Makoto. The next day, Makoto asks Kotonoha to be his girlfriend, and she accepts. While waiting to begin their first date, Makoto thanks Sekai repeatedly for setting him up with Kotonoha and asks how he can repay her. Sekai responds by kissing Makoto on the lips, saying that it was enough as a reward, and gets on the train, wishing Makoto luck on his date. On the next scene, Sekai is shown crying in grief during a ride back home.