Clannad - Season 1 Episode 22 Two Shadows

After Nagisa finds out about her parents' secret past, she cannot take her mind off how she ruined their dreams, and becomes emotional and depressed. On the day of the school festival, the whole theater club realizes that Nagisa is not herself, and try to cheer her up, but to no success. As the performance starts, Nagisa breaks down, but with encouragement from Akio, who said that Sanae's and his dream was for Nagisa to make her dream come true, the play was a huge success. The next day as the sun is setting, Tomoya finally confesses his love to Nagisa in the club room. This comes as a shock for Nagisa, causing her to cry tears of joy.