K-On!/Tear Jerker

"At the train station, on the path by the river, no matter how far we are, we can look up to the same sky and sing as one! But you know, I met a wonderful angel. Graduation isn't the end, because we're best friends from now on. If you say "I LOVE YOU!", we'll reply "WE REALLY REALLY LOVE YOU!!" We won't lose anything, forever and ever we'll always be together."
 * The end of episode 20 in K-On!'s second season has the seniors breaking down in tears after their final festival concert, realizing they're approaching the end of their high school days.
 * Episode 24 of the second season. Especially because of the lyrics of the song the club sings at the end.
 * Especially the last two verses:

"I'm so sorry. I only now just realized, I've been taking you for granted. So, to start with, I have to tell you, thank you so much!"
 * The lyrics to U&I. It's obvious Yui is talking about her little sister Ui and how she doesn't know what to do without her. It's mostly cute and moe ("Where's the soy sauce and the sugar? Without you I can't do anything." etc.), but near the end of the song, it seems Yui has finally realized how important her little sister is to her, and how they won't be able to be together much longer: