Hi, 

I remember the plot of this Japanese movie/drama but I don't remember the name of the show or the actors. The plot revolves around a senior high school boy and a freshman girl. The boy has two friends in his class, a boy and a girl. He is not that invested in school, he lives with his stepmom(and dad?) and their relationship is rocky. The girl is bullied. The two of them become friends and they find an abandoned storage shed on the school property which they use as their private hideaway, they also set up an aquarium there with a fish.  The girl lives with her mother. Anyway, if any of this rings a bell for someone, please let me know. Thanks. 

Kingyo Club or Goldfish Club, one of my faves mini jdrama.

wow, thank you so much Czakhareina! It was driving me crazy not being able to find it :)

You are welcome. Glad to have help...